Biology Final Review

BSC2011C Final Review Unit 1 Review Ch. 25, 22, 23, 24, 26, 19, 27 Ch. 25 1. Life is metabolism and heredity. Metabolism is the mechanism that creates order and complexity from chaos, by acquiring and expending energy. Heredity is the ability of an organism to copy itself and it is broken down into: i. Multiplication, ii. Inheritance, iii. Variation. 2. DNA codes via RNA for 20 of naturally occurring amino acids. Amino Acids are the building blocks of proteins and bodies. DNA stores and transmits hereditary information, but proteins do most of the work. DNA IS THE UNIVERSAL DIGITAL CODE FOR LIFE. To replicate and synthesize proteins, DNA relies on the pre-existence of protein molecules and RNA molecules. 3. RNA is the bridge between DNA and proteins, via mRNA for transcription and rRNA for translation. Thus, RNA can survive on its own while DNA relies on the existence of RNA and proteins, with them DNA is helpless. 4. The 4 points of “first life” are: 1. The Abiotic (non-living) synthesis of small organic molecules, such as amino acids and nucleotides. 2. The joining of these small molecules into macromolecules, including proteins and nucleic acids. 3. The packing of these molecules into “protobionts,” droplets with membranes hat maintained an internal chemistry different from that of their surroundings. 4. The origin of self-replicating molecules that eventually made inheritance possible. 5. The first cells to develop occurred in this order: Monomers > Polymers > Protobionts > RNA ‘world’ > DNA protobionts > first cell. 6. Fossils are the evidence of life and evolution. Organisms trapped in sediment > remain mineralized with hard and soft parts. 7. Fossils can be dated by two methods: Radiometric dating & Magnetism. In Radiometric dating, the age is based on the decay of radioactive isotopes. A radioactive “parent” isotope decays to a “daughter” isotope at a constant rate. The rate of decay is expressed by the half-life, the time requires for 50% of the parent isotope to decay. In Magnetism, the formation of volcanic and sedimentary rocks, iron particle in the rock align themselves with Earth’s magnetic field. 8. The fossil record is based primarily on the sequence in which fossils have accumulated in sedimentary rock layers called “strata.” 9. The first two eons – the Archaean and the Proterozoic – together lasted approximately 4 billion years. The Phanerozoic eon, has last roughly the last half billion years, and encompasses most of the time hat animals have existed on Earth.

10. Early prokaryotes were Earth’s sole inhabitants from at least 3.5 BYA – 2.1 BYA. Atmospheric O2 increased gradually from 2.7-2.2 BYA, but shot up rapidly to more than 10% of its present level. The first eukaryotes began to appear about 2.1 BYA, multicellular eukaryotes evolving around 1.5 BYA. Many living animals appeared during the Cambrian period which was approximately 535-525 MYA. 11. The order of time is three eons which have last approximately 4.6 billion years. The order is Eons > Era > Period > Epoch. 12. Methods in which parokaryotes derived energy: Autotrophs (synthesize needed organic molecules), Chemotrophs (energy from sulfur or methane), Photoautotrophs (photosynthesize to split water and liberate O2 generating energy). 13. Life falls into three domains: Eukarya, Archaea, Bacteria 14. Anaerobic respiration: 1 glucose + 2 water  Aerobic respiration: 1 glucose + 6 oxygen  1 lactic acid + 2 ATP 6 C02 + 6 H20 + ca. 30 ATP

15. Small prokaryotes enter host as (undigested) prey or parasitesHost & invader gain mutual advantages (e.g. energy from mitochondrial ancestors) Host & endosymbionts become single organism. The evidence for this is: Organelle structure & biochemistry homologous to living prokaryotes (e.g. homologous electron transport mechanisms). Organelle replicates by binary fission, as do prokaryotes. Organelles possess their own DNA which, as in prokaryotes contains a single, circular DNA molecule with little associated proteins. Organelles, like free-living prokaryotes have cellular machinery to transcribe and translate DNA into proteins 16. The “oxygen revolution” refers to the time when atmospheric oxygen was gradually increasing (2.7 – 2.2 bya) and then shot up relatively rapidly to more than 10% of its present level, which had an enormous impact on life. 17. Mitochondria  probably derived from alpha proteobacteria . Plastids  probably derive from certain cyanobacteria 18. In a relatively short period of time (10 million years), the Cambrian explosion yielded a major diversification of life on earth. Some of these changes included: emergence of claws, new defensive adaptations, among other adaptations for survival. 19. A mass extinction results in which large numbers of a species become extinct throughout Earth. There are five mass extinctions documented in the fossil record over the past 500 million years. The most notable occurred during the Permian and Cretaceous. The Permian claimed approximately 96% of marine animal species and drastically altered life in the ocean, and it occurred in what is now Siberia. The Cretaceous extinguished more than half of all marine species and eliminated many families of terrestrial plants and animals. 20. Plate tectonics refer to a dynamic Earth. Not only do organisms evolve, the Earth is evolving as well. The continents are part of great plates of Earth’s crust that essentially float on the hot, underlying portion of the mantle. These plates move over time in a process called (continental drift). Plates move slowly, but their cumulative effects are dramatic.

21. The fossil record indicates that the diversity of life has increased over the past 250 million years. This increase has been fueled by adaptive radiation, periods of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles, or niches in their communities. 22. Many striking evolutionary transformations are the result of heterochrony, an evolutionary change in the rate or timing of developmental events. 23. If reproductive-organ development accelerates compared to other organs, the sexually mature stage of a species may retain body feature that were juvenile structures in an ancestral species – a condition called paedomorphosis. Ch. 22 1. There is roughly 1.4 – 1.6 million described species on Earth, with approximately 30 million or more that have still yet to be discovered. 2. The mechanisms for the diversification of life include: Non evidence-based (non-scientific) explanations and Evidence-based (scientific) explanations. 3. Darwin’s idea of evolution was that organisms change with time and become or continue to adapt to their environment. Lamarck’s idea on evolution was use and disuse, as well as inheritance of ACQUIRED traits. This is wrong, because only traits coded in the genome of DNA are passed on. 4. The concept of use and disuse implies that parts of the body that are used extensively become larger and stronger, while those that are not used deteriorate. This was a false prediction by Lamarck. 5. Inheritance of acquired characteristics was constructed by Lamarck and stated that characteristics acquired by an individual, such as large muscles from body building, would be passed on to their offspring, a false construction by Lamarck. 6. Inherited traits are ones obtained from a parent that is coded in the DNA genome. In contrast, acquired traits are created within an individual and not passed on. 7. The premises for evolution by Natural Selection made by Darwin were/are: 1. Members of a population often vary greatly in their traits. 2. Traits are inherited from parents to offspring. 3. All species are capable of producing more offspring than their environment can support. 4. Owing to lack of food or other resources, many of these offspring do not survive. From these premises two inferences were made: 1. Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals. 2. This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations. 8. The definition of modern evolution is a change in allele frequency in a population over time. Populations evolve, individuals do not. The allele change is in an individual, but the change is in the population over time.

9. Life did not evolve in huge leaps. Rather, small changes over time was the cumulative effect of evolution, a process called Gradualism. 10. The components of natural selection include several adaptations, which are traits that are favored. These include: Morphological traits, Behavioral traits, Physiological traits. 11. The evidence for evolution include: Artificial selection (human altering outcomes), Fossils, Homology (similar features in closely related species), Convergence, Biogeography, Direct Evidence (HIV evolving to resist medications), Molecular homology (similar DNA sequences Human/Primate) 12. Vestigial structures are remnants of features that server important functions in the organism’s ancestors. 13. Convergent evolution is that independent evolution of similar features in different lineages. 14. Key points to remember: 1. Natural Selection is a process of editing rather than a creative mechanism, 2. Natural selection depends on time and place. Ch. 23 1. Microevolution is defined as changes in allele frequencies in a population from generation to generation. Macroevolution occurs above the species level such as the emergence of a new organism or a broad change in the evolutionary trend. 2. Gregor Mendel showed that organism transmit discrete heritable traits, which we now call genes, onto their offspring. 3. Average heterozygosity is the average percent of loci that are heterozygous (2 different alleles). 4. Define the following: Genotype – is the genetic makeup, or set of alleles, of an organism (ex. C^R C^W) Phenotype – is the physical and physiological traits of an organism, which are determined by its genetic makeup (genotype). Mitosis – is a process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Mitosis converse chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei. Meiosis – is a modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round DNA replication. It results in cell with half the number of chromosome sets as the original cell. Genes – is a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Loci – is a specific place along the length of a chromosome where a given gene is located. Somatic Cell – is any cell in a multicellular organism except a sperm or egg. Homologous Pairs – is a pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organism’s father, the other from the mother.

Zygote – is the diploid product of the union of haploid gametes during fertilization; a fertilized egg. Allele – is any of the alternative versions of a gene that produce distinguishable phenotypic effects. Mutation – is a change in the nucleotide sequence of an organism’s DNA, ultimately creating genetic diversity. Mutations also can occur in the DNA or RNA of a virus. 5. A population is a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring. A gene pool consists of all the alleles for all the loci in all individuals of the population. 6. The H-W equation was developed and is used to test (calculate) whether a population is evolving. 7. When using the H-W equation, five factors must be present in order for the equation to function. These are: (1) No mutations by altering alleles or deleting or duplicating entire genes, mutations modify the gene pool, (2) Random mating if individuals mate preferentially within a subset of the population, random mixing of gametes does not occur, and genotype frequencies change, (3) No natural selection differences in survival and reproductive success of individuals carrying different genotypes can alter allele frequencies, (4) Large population the small the population, the more likely it is that allele frequencies will fluctuate by chance from one generation to the next (genetic drift), (5) No gene flow by moving alleles into or out of populations gene flow can alter allele frequencies. 8. The mechanisms of evolution are: Migration (gene flow), mutation, non-random mating, natural selection and genetic drift. 9. The relative fitness of an individual refers to the contribution that individual makes to the gene pool of the next generation, relative to the contribution of other individuals. 10. Natural selection can alter the frequency distribution of heritable traits in three ways, depending on which phenotypes in a population are favored, and these three are: Directional selection - occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting the frequency curve for the phenotypic character in one direction or the other. Disruptive selection – occurs when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes. Stabilizing selection – acts against both extreme phenotypes and favors intermediate variants. This mode of selection reduces variation and tends to maintain the status quo for a particular phenotypic character.

11. Genetic variation comes from mutation and sexual recombination. Mutations are rare, but new genes and alleles can only arise from this. NEUTRAL VARIATION • 20 amino acids • 43 triplet codons = 64 permutations • Redundancy > 1 triplet codon – same amino acid • Many point mutations have no effect : these are NEUTRAL (neither favored nor unfavored). Will remain at Hardy-Weinberg equilibrium. • Neutral mutations accumulate freely in non-coding genes. These are useful in molecular phylogeny Most mutations are neutral (no phenotypic effect) Others have a neutral phenotype effect, - i.e. no impact on reproductive success) e.g. human fingerprints - Others are deleterious – e.g. phenylketoneuria – leads to mental retardation Very few mutations are advantageous – confer a new benefit and rapidly SPREAD into gene pool (e.g. genes coding for antibiotic resistance in bacteria). Mutations that alter gene number or sequence • Mutations involving multiple chromosomes or missing/duplicated entire chromosomes usually deleterious. • Gene duplication: can be beneficial – allow diversification of protein coding. E.g. remote ancestors of mammals carry 1 olfactory gene, mammals have hundreds. Sexual recombination encompasses independent chromosome orientation (meiosis), crossing over, and random fertilization of gametes. 12. Natural Selection cannot fashion perfect organisms for the following reasons: 1. Selection can act only on existing variations. 2. Evolution is limited by historical constraints. 3. Adaptations are often compromises. 4. Chance, natural selection, and the environment interact. With these four constraints, evolution cannot craft perfect organisms. Ch. 24 1. Natural selection generates phenotypic adaptations. These adaptations can include: Morphological adaptations (cryptic skin color), Behavioral adaptations (mutual grooming), Physiological adaptations (enzyme synthesis in biochemical pathways). 2. Microevolution is the changes noted in allele frequencies in a population evolutionary change below the level of speciation. Some of this includes: Migration, non-random mating, genetic drift (including bottleneck effect), mutation (source of novel variation), and natural selection (source of adaptation). Whereas, Macroevolution is the broad patterns of evolution over long time spans, this includes: The origin of new taxonomic groups (new species, new genera, new families, new kingdoms). 3. A species is an organism that forms with distinct: Morphology, Physiology, Behavior, DNA sequences. Usually species exhibit distinct differences in some or all of these parameters.

4. The biological species concept is defined as: A group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring – but do not produce viable, fertile offspring with member of other such groups. 5. A new species can arise from two concepts: 1. All populations have the capacity to interbreed and 2. There is no interbreeding with other species. Therefore, New breeding population  Evolution  Reproductive isolate  New Species  Biodiversity. 6. Reproductive isolation refers to gene flow barriers that act against different species mating and producing fertile offspring. They are broken down into: Prezygotic barriers (impede mating or fertilization) and Postzygotic barriers (prevents successful propagation of offspring). Prezygotic Barriers:  Habitat isolation – Two species that occupy different habitats within the same area may encounter each other rarely, if at all.  Temporal isolation – Species that breed during different time of the day, different seasons, or different years cannot mix their gametes.  Behavioral isolation – Courtship rituals that attract mates and other behaviors unique to a species are effective reproductive barriers, even between closely related species.  Mechanical isolation – Mating is attempted, but morphological differences prevent its successful completion.  Gametic isolation – Sperm of one species may not be able to fertilize the eggs of another species. Postzygotic Barriers:  Reduced hybrid viability – The genes of different parent species may interact in ways that impair the hybrid’s development or survival in its environment.  Reduced hybrid fertility – Even if hybrids are vigorous, they may be sterile. If the chromosomes of the two parent species differ in number or structure, meiosis in the hybrids may fail to produce normal gametes. Since the infertile hybrids cannot produce offspring when they mate with either parent, genes cannot flow freely between species.  Hybrid break – Some first-generation hybrids are viable and fertile, but when they mate with another or with either parent species, offspring of the next generation are feeble or sterile. 7. The problems with the biological species concept include: 1. Not applicable to asexual organism, 2. Difficult to apply to fossils or organisms with poorly known reproductive habits, 3. Viable hybrids, 4. Species sometimes merge geographically “ring species.” 8. The mechanisms of speciation include: Allopatric speciation and sympatric speciation.  Allopatric speciation – Gene flow is interrupted when a population is divided into geographically isolated subpopulations.  Sympatric speciation – Speciation occurs in populations that live in the same geographic area. 9. When reproductive isolation fails, the formation of a hybrid zone takes place. Within this zone there are three possible outcomes.

10. The outcomes for a hybrid zone are: reinforcement, fusion, and stability.  Reinforcement – Strengthening or reproductive barriers-hybrids gradually cease to be formed.  Fusion – Weakening of reproductive barriers-the two species fuse  Stability – Continued production of hybrid individuals. 11. Allopatric speciation occurs mostly when: 1. Barrier isolates a small founder population from main population 2. Prolonged separation of populations 3. No genetic exchange (requires a substantial barrier) 4. New sets of selective pressures for isolated population (environment is different) 5. New environment has plentiful resources and is relatively free of incumbent competitors Sympatric speciation occurs mostly when: 1. Gene flow to and from the isolated subpopulation is blocked 2. When a subset of a population becomes reproductively isolated because of natural selection that results from a switch to a habitat or food source not used by the parent population 12. Heterochrony – Evolutionary change in the timing or rate of an organism’s development. 13. Paedomorphosis – The retention in an adult organism of the juvenile features of its evolutionary ancestors. 14. Homeotic genes – determine expression of other genes during embryonic development, such as where wings or legs might appear. Regulator genes – codes for a protein, such as a repressor, that controls transcription of another gene or group of genes. Ch. 26 1. Taxonomy is the naming and classification of organisms, while systematic is the study of how organisms are evolutionary evolved. 2. Phylogeny is the evolutionary history of a species or taxon. It is used by sytematists to classify organisms and determine evolutionary relationships. 3. The hierarchical sequence is: Species, Genus, Family, Order, Class, Phylum, Kingdoms, and Domain 4. Phylogenetic tree – Is a pattern of lineage branching that represents the evolutionary history of organisms. 5. The root of a phylogenetic tree represents the basal common ancestor of the rest of the tree. While each node on the tree is a “common ancestor,” and the terminal node represents an extinct or extant species. 6. Sister taxa refer to two organisms that share an immediate common ancestor.

7. Cautions to take into consideration when referencing a phylogenetic tree are:  Branching does NOT mean actual age.  Branching does not imply in sister taxa that one evolved from the other, only that they share an immediate common ancestor. *Remember* Phylogenetic trees are a hypothesis based on all of the available data. 8. Phylogenetic trees are based on SHARED DERIVED CHARACTERS (SYNAPOMORPHY). 9. When referencing cladistics, there are three types of groups: monophyleic, paraphyletic, and polyphyletic.  Monophyletic group – signifies that it consists of an ancestral species and all its descendants.  Paraphyletic group – signifies that it consists of an ancestral species and some, but not all of its descendants.  Polyphyletic group – signifies that it consists of taxa with different ancestors. 10. A synapomorphy defines a monophyletic group due to shared derived characteristics (homologies) 11. Homologous traits are derived by shared common ancestry. In contrast, analogous traits are derived independently, and not inherited from a common ancestor, usually the result of convergent evolution. 12. Homologous structures are variations on structure themes that are present in a common ancestor. The structures all evolved from the same skeleton, but are rearranged to function in different ways. 13. Convergent Evolution occurs when taxa are presented with similar environmental challenges, and often evolve similar traits are structures. 14. Synapomorphies are obtained from two sets of data: morphological, which comes from fossils and living organisms. They are also obtained from molecular/genetic, which can only be obtained from living organisms. 15. Molecular phylogenies is the practice of comparing DNA sequences between a species that are closely related. The DNA is identical during the beginning split into two populations; there are insertions and deletions that cause a new species to arise. When this occurs the previously homologous regions do not align; therefore, systematists must use computer software to align the once homologous regions. 16. By chance, when two species have DNA that is homoplasic, they share some of their base sequences. Usually by convergence, this occurs roughly 25% of the time. 17. Synapomorphies are shared, derived traits, whereas Plesiomorphies are ancestral traits. 18. Maximum Parsimony is a principle that states when considering multiple explanations for an observation, one should first investigate the simplest explanation that is consistent with the facts. Maximum Likelihood as applied to systematics, a principle that states that when considering multiple phylogenetic hypotheses, once should take into account the hypothesis that reflects the most likely sequence of evolutionary events, given certain rules about how DNA changes over time.

19. An outgroup is a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying, (the ingroup) An ingroup is a species or group of species who evolutionary relationships we seek to determine. 20. Orthologous genes are ones that are present in the same place on the chromosome of two different species. These sequences are called MARKERS. 21. Calibration of molecular clocks can be accomplished by two points: 1. Minimum dates for a node can be derived from fossil evidence, this is best used with a couple of dates for a two point calibrations. 2. Well dated geological events, which split distributions. 22. Life was originally classified into two kingdoms: Plants & Animals. Then it was reclassified into 5 kingdoms: Prokaryotes, Protista, Plants, Fungi, and Animals. Then, into 3 domains: Archaea, Eukarya, Bacteria. Ch. 19 1. Viruses are among the simplest of biological systems. They are not placed in the three domains because: 1. Viruses lack metabolic machinery of cells, little more than genes in a protein coat, 2. They have a genome, and replicate but can only do so within the cell of a host. Viruses subvert the host’s replicating system to copy themselves. 2. Viruses do exhibit some properties of life:  They replicate and undergo Darwinian evolution.  They have a genotype and phenotype (structure of protein coat, modification of host phenotype). 3. Properties of life that are absent are: Metabolism, when a virus is alone, they are completely dormant with no biological activity. Viruses that are active manipulate the host’s metabolism. 4. The first virus was from a tobacco plant, and was come to be known as the tobacco mosaic virus. The initial identification was proven to be difficult, because they could not be seen by microscopes of the time. 5. The virus structure consists of:  Non-cellular  Protein coat surrounding nucleic acid  DNA or RNA (double or single stranded)  “DNA viruses”  “RNA viruses”  Linear or circular stand of DNA/RNA with 4 to 100s of genes. 6. Viral genes accomplish the following:  Force the host to copy the viral genome  Force the hose to build protein coast for the copied viral genome

7. Viruses can be categorized into the following groups and are classified as DNA or RNA virus:  Helical  Isosahedral - (glycoproteins extending from the outer portion of the virus adhere to hose cells with these)  Enveloped - (the envelope is derived from host membrane. Therefore, host does not recognize as foreign)  Complex - (largest viruses, such as bacteriophages)  Capsid - (protein shell of virus; Capsomere unit of capsid—self assemble to form capsid) 8. Each type of virus can infect cells of only a limited variety of hosts, called the host range of the virus. This host specificity results from the evolution of recognition system by the virus. Viruses identify host cell by a “lock-and-key” fit between viral surface proteins and specific receptor molecules on the outside of cells. 9. Viruses can be classified into DNA viruses or RNA viruses, which can be categorized into double or single stranded enveloped or non-enveloped, isosahedral or circular etc etc. 10. Enveloped viruses are derived from the host membrane. This causes the hose to not recognize the virus as foreign. This is due to the glycoproteins, which are not recognized as antigens. 11. There are five steps during the cycle of virus exposure: Attachment>Penetration>Replication>Assembly>Rlease. 12. There are 2 modes to virus reproduction: Lytic mode & Lysogenic mode.  Lytic mode: A phage reproductive cycle that culminates in death of the host cell. The term refers to the last stage of infection, during which the bacterium lyses (breaks open) and releases the phages that were produced within the cell. A phage that only reproduces by the lytic cycle is a virulent phage.  Lysogenic mode: Allows replication of the phage genome without destroying the host. Phages capable of using both modes (Lytic/Lysogenic) are called temperate phages. 13. Retroviruses are the only ones which carry the enzyme reverse transciptase. 14. Viruses cause disease by several factors: Toxic viral shells, Cellular lysis, and Cellular resource depletion. Some of the symptoms are selected by the viral genome to aid in transmission, such as sneezing or skin sores. 15. Viruses require hosts, so must have originated SINCE hosts evolded. There are two main theories to the origin of viruses: 1. Break away portions of host genomes: mobile genetic elements: e.g. transposons: DNA fragments that can move arounse genome. 2. Intracellular parasites that have eliminated all but their genome. 16. Prions: Misfolded proteins (no nucleic acids), Cause degenerative neural disease, Resistant to heat and other sterilization methods, Long incubation periods (~10 years). Prions turn normal proteins into other prions by physical contact; they also form plaques on the brain (causing cavities).

Ch. 27 1. A prokaryotic cell (prokaryote) is a type of cell lacking a membrane-enclosed nuclease and membraneenclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes. 2. The structure of a prokaryote is:  No membrane-enclosed nucleus  No organelles  No mitosis or meiosis  Mostly asexual reproduction (binary fission), but do undergo genetic exchange in some cases  Asexual reproduction in eukaryotes would take time due to the length of generations. 3. When referencing prokaryotes, there are three basic morphologies: Spherical (cocci), Rod-shaped (bacilli), Spiral 4. The cell wall of a prokaryote is comprised of the plasma membrace, a layer of peptidoglycan (cell wall) which provides structure and osmotic protection. Gram staining is the process that distinguishes between different species based on their cell wall. Gram-negative bacteria are usually more pathogenic and more resistant to antibiotics (protective layer of lipopolysaccharides), the lipid components are often toxic. 5. The most common structure prokaryotes use to move is the flagella. In a uniform environment, flagellated prokaryotes tend to move around freely. However, in a heterogeneous environment, many exhibit taxis, the movement toward or away from a stimulus. 6. Prokaryotes multiply by Binary fission (no meiosis or mitosis, rather cell division). Genetic recombination occurs by: 1. Transformation and Transduction, 2. Conjugation (plasmid transfer, plasmid/chromosome recombination). 7. Note: Genetic variation comes from mutation and genetic recombination. Binary fission does not involve genetic recombination, it is ASEXUAL reproduction. Bacteria do ungergo recombination by the exchange of genetic information from: A. Conjugation and plasmids, B. Transformation and Transduction. Example: F+ cell contain an F plasmid with F factor (genes required for production of sex pili). The F factor is integrated into bacterial chromosome>DNA including F factor copied and transferred into other cell via sex pilus>Exchange of homologous genes between transferred and recipient DNA sequences=recombination>Transferred DNA then broken down. Here the recipient cell has received genes but not the F factor. 8. Transformation – Occurs when prokaryotes absorb DNA through their cell walls. Transduction – Transfer of DNA from one bacterium to another via phages (viral transfer). Phage sometimes carry random bit of bacterial chromosome following lysis. 9. Refer to 7. 10. To make a sex pilus, the cell must contain a “conjugative plasmid” the F-plasmid (F-factor). An F- cell is one that does not contain the conjugative plasmid.

11. Archae, are unlike bacteria due to: No peptidoglycan in cell well, growth is not inhibited by antibiotics, and there are Extremophiles, which can live in specialized environments. 12. Symbiotic relationships include: mutualism, commensalism, and parasitism)  Commensalism – One partner gains, while the other does not gain or lose.  Symbiotic – Both partners gain (benefit) in some way.  Parasitic – One partner gains (benefits), while the other loses. 13. Exotoxins, which are secreted by bacteria function by:  Cause ion channels to open in intestinal lining  Causing the release of chloride ions  Body loses water into intestines by osmosis Ultimately MASSIVE WATER LOSS (dehydration) Unit 1 END Brian’s Review-> Lec 10 1. A eukaryote is a type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles (such as mitochondria and golgi apparatus). Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called Eukaryotes. 2. A “protist” is an informal term given to eukaryotes that is not a plant, animal, or fungus. Most protists are unicellular, though some are colonial or multicellular. 3. In eukaryotic evolution, it is suggested that protest diversity has much of its origins in endosymbyosis, the process in which certain unicellular organisms engulf other cells, which become endosymbionts and ultimately organelles in the host cell. In some instances, during eukaryotic evolution, red algae and green algae underwent secondary endosymbiosis. They were ingested in the food vacuole of heterotrophic eukaryotes and became endosymbionts themselves. 4. The four major feeding styles of protists are: 1. Photoautotroph (plant-like), Grade: Algae 2. Ingestive (heterotrophs – food particles) ‘animal-like’ Grade: Protozoa 3. Absorptive (heterotrophs – organic molecules) ‘fungus-like’ Grade: Oomycetes + others 4. Photosynthetic/Heterotrophic (mixotroph) ‘animal/plant-like (Euglena)

5. Prostist clade breakdown: Excavata: Consists of the diplomonads, parabasalids, and euglenozoans.  The Diplomonads and Parabasalids both lack plastids but each have modified mitochondria. Most of these two are found in anaerobic environments.  Diplomonads have modified mitochondria called mitosomes. These lack functional electron transport chains and hence cannot use oxygen to help extract energy from carbohydrates and other organic molecules; they instead use anaerobic biochemical pathways, such as glycolysis.  Parabasalids also have reduced mitochondria; called hydrogenosomes, these organelles generate some energy anaerobically, by releasing hydrogen gas as a by-product.  Euglenozoans: Belong to a diverse clade that includes predatory heterotrophs, photosynthetic autotrophs, and parasites. The main morphological feature that distuingishes protists in this clade are the presence of a spiral or crystalline rod of unknown function inside their flagella.  Kinetoplastids have a single, large mitochrondrion that contain an organized mass of DNA called kinetoplast.  Euglenids have a pocket at one end of the cell from which one or two flagella emerge. Many species of euglenids are mixotrophs: In sunlight they are autotrophic, but when sunlight is unavailable, they can become heterotrophic (using phagocytosis). Chromaveolata: A large, extremely diverse clade of protist that has recently been proposed on two lines of evidence. First, some DNA sequence data suggest that the chromalveolates form a monophyletic group. Second, some data support the hypothesis that the chromalveolates originated more than a billion years ago, when a common ancestor of the group engulfed a single-celled, photosynthetic red alga.  The Alveolates are a group of protists whose monophyly is well supported by molecular systematic. Structurally, the species in this group have membrane-bounded sacs just under the plasma membrane. The functions of these are unknown; hypothesis states that they may help stabilize he cell surface or regulate the cell’s water and ion content. The alveolates include three subgroups: flagellates (dinoflagellates), apicomplexans, and the ciliates.  The Stramenopiles are a group of marine algae that include some of the most important photosynthetic organisms on the planet, as well as several clades of heterotrophs. The diatoms are unicellular algae that have a unique glass-like wall made of hydrated silica embedded in an organic matrix. The golden algae has a characteristic color is caused by their yellow and brown carotenoids, their cells are typically biflagellated, with both attached near one end of the cell. The brown algae are the largest and most complex, all are multicellular and most are marine, and they are most common along temperate coasts where water is cool. Rhizaria: has recently been proposed based on result from molecular systematics. DNA evidence suggests that they are a monophyletic group. Many species in Rhizaria are among the organisms referred to as amoebas. The protists called foraminiferans or forams are named for their porous shells, called tests. These tests consist of a single piece of organic material hardened with calcium carbonate. The protists called radiolarians have delicate intricately symmetrical internal skeletons that are generally made of silica. The pseupodia of these mostly marine protists radiate from the central body. Archaeplastida: is a monophyletic group that descended from the ancient protist that engulfed a cyanobacterium. This consists of Red Algae, Green Algae (chlorophytes and charophytes), Land plants.

Unikonta: is a recent proposed, extremely diverse super-group of eukaryotes that includes animals, fungi, and some protists. There are two major clades: amoebozoans (slime molds, plasmodial slime molds) and the opisthokonts (includes animals, fungi, and several groups of protists). Lec 11 1. Fungi are heterotrophs that feed by absorption. 2. Unicellular fungi are yeasts. Yeasts often inhabit moist environments, including plant sap and animal tissues, where there is a ready supply of soluble nutrients, such as sugars and amino acids. 3. The morphology of multicellular fungi enhances their ability to grow into and absorb nutrients from their surroundings. The bodies of these fungi typically form a network of tiny filaments, which are called hyphae. These consist of tubular cell walls surrounding the plasma membrane and cytoplasm of the cell. Fungal hyphae form an interwoven mass called a mycelium that infiltrates the material on which the fungus feeds. A mycelium’s structure maximizes its surface to area volume ratio, making feeding more efficient. Two forms of hyphae septate hypha (septum allowing organelles to flow from cell to cell), coenocytic hyphae consist of a continuous cytoplasmic mass having hundreds or thousands of nuclei. 4. Unlike plant cell walls, which contain cellulose, fungal cell walls are strengthened by chitin. This strong but flexible nitrogen-containing polysaccharide is also found in the external skeletons of insects and other arthropods. 5. Fungi reproduction:  Sexual – Generally, sexual reproduction begins when hyphae from two mycelia release pheromones. Next, the union of the cytoplasms of two parent mycelia occurs and is known as plasmogamy. In most fungi, the haploid nuclei contributed by each parent do not fuse right away; instead, parts of the fused mycelium contain coexisting, genetically different nuclei. This type of mycelium is known as heterokaryon (different nuclei). In some species, the different nuclei may exchange chromosomes and genes in a process similar to crossing over; this is known as dikaryotic (two nuclei). Hours, days or even centuries may pass between plasmogamy and the next stage in the sexual cycle karyogamy. During karyogamy, the haploid nuclei contributed by the two parents fuse, producing diploid cells. Zygotes and other transient structures form during karyogamy, the only diploid stage in most fungi. Meiosis then restores the haploid condition leading to the formation of spore that enables fungi to disperse.  Asexual – Many fungi reproduce asexually by growing as filamentous fungi that produce (haploid) spores by mitosis; such species are known informally as molds if they form visible mycelia. Molds typically grow rapidly and produce many spores asexdually-enabling the fungi to colonize new sources of food. Many species that produce such spores can also reproduce sexually if they happen to contac a member of their species of a different mating type. Other fungi reproduce asexually by growing as single-celled yeasts. Instead of producing spores, asexual reproduction in yeasts occurs by ordinary cell division or by the pinching of small “bud cells” off a parent cell. 6. Fungi are related to animals in that they both evolved from a unicellular flagellated ancestor, but multicullularity in fungi and animals evolved independently. The molecular clock analysis estimates that the ancestors of animal and fungi diverged into separate lineages about one billion years ago. However, the oldest undisputed fossils of fungi are only about 460 million years old.

7. Much of the fungal diversity we observe today may have originated during an adaptive radiation that began when multicellular plants and animal colonized land. For example, fossils of the earlier known vascular plant from the late Silurian period contain evidence of mycorrhizal relationships between plants and fungi. Plants probably excited in this beneficial relationship with fungi from the earlier period of colonization of land. 8. Fungi play important key roles in nutrient cycling, ecological interactions, and human welfare.  Fungi as Decomposers: Fungi are well adapted as decomposers of organic material, including the cellulose and lignin of plant cell walls. In fact, almost any carbon-containing substrate can be consumed by at least some fungi. Fungi and bacteria are responsible for keeping ecosystems stock with the inorganic nutrients essential for plant growth. Without decomposers, carbon, nitrogen, and other elements would remain tied up in organic matter. Plants and the animal that eat them could not exist because elements taken from the soil would not be returned. Without decomposers, life as we know it would cease.  Fungi as Mutualists: Fungi may form mutualistic relationships with plants, algae, cyanobacteria, and animals. Fungus-Plant, all plant species studied to date appear to harbor symbiotic endophytes, fungi that live inside leaves or other plant parts without causing them harm. Fungus-Animal, some fungi may be present in the gut of cattle and other grazing mammals, assisting them in the breakdown and digestion of plant material. Lichen, is a symbiotic association between a photosynthetic microorganism and a fungus in which millions of photosynthetic cells are held in a mass of fungal hyphae. Lichens grown on the surfaces of rocks, rotting logs, trees, and roofs in various forms. Fungi-Pathogens, bout 30% of the 100,000 known species of fungi make a living as parasites or pathogens, mostly of plants. Lec 12 1. The first types of plants on land are believed to be green algae. These appeared during the Ordovician around 475 million years ago. There are four key derived traits: 1. Rosette-shaped cellulosesynthesizing complexes, 2. Peroxisome enzymes (more efficient respiration), 3. Structure of flagellated sperm, 4. Formation of phragmoplast 2. The origin of vascular plants is dated around 420 million years ago. 3. Plants belong to the supergroup kingdom Plantae. 4. There are five main plant traits: Apical Meristems – these are very rapid cell division areas, and they are found in the tip of shoot or roots. The cells produced here can differentiate into outer epidermis cell to protect the body, or various types of internal tissues. Shoot apical meristems also generate leave in most plants. Alteration of Generations – The life cycles of all land plants alternate between two generations of multicellular organisms (gametophytes and sporophytes). The names of the two multicellular generations of the plant life cycle refer to the reproductive cell they produce; Haploid gametophytes and diploid sporophytes. Walled spores produced in sporangia – The polymer sporopollenin makes the walls of plant spores tough and resistant to harsh environments. Multicellular gametangia – Another feature distinguishing early lanf plant from their algal ancestors was the production of gametes within multicellular organs called gametangia. The female archegonia (pear shaped) produces eggs, while the male antheridia produces sperm and released them. Multicellular dependent embryos (diploid) – embryo, maternal tissue, placental transfer (mammal like)

5. The following 4 distinctive traits are shared between charophyceans (charophytes) and land plants:  Rosette-shaped cellulose-synthesizing complexes, the cells of both land plants and charophytes have circular, petal-shaped arrays of proteins in the plasma membrane. These protein arrays synthesize the cellulose microfibrils of the cell wall. In contrast, noncharophyte algae have linear arrays of proteins that synthesize cellulose.  Peroxisome enzymes, the peroxisomes of both land plants and charophytes contain enzymes that help minimize the loss of organic productsas a result of photorespiration. The peroxisomes of other algae lack these enzymes.  Structure of flagellated sperm, in species of land plants that have flagellated sperm, the structure of the sperm closely resembles that of charophyte sperm.  Formation of a phragmoplast, particular details of cell division occur only in land plants and certain charophytes, including the genera Chara and Coleochaete. For example, in these organisms a group of microtubules known as phragmoplast forms between the daughter nuclei of a dividing cell, a cell plate then develops in the middle of the phragmoplast, across the midline of the dividing cell. The cell plate, in turn, gives rise to a new cross wall that separates the daughter cells. 6. The Alteration of Generations is a life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae.  Sporopollenin – A durable polymer that covers exposed zygotes of charophyte algae and forms the wall of plant spore, preventing them from drying out.  Gametophyte – In organisms (plant and some algae) that have alteration of generations, the multicellular haploid form that produces haploid gametes by mitosis. The haploid gametes unite and develop into sporophytes.  Sporophyte – In organisms (plants and some algae) that have alteration of generations, the multicellular diploid form that results from the union of gametes. The sporophyte produces haploid spores by meisosis that develop into gametophytes.  Spore(s) – (1) In the life cycle of a plant or alga undergoing AoG, a haploid cell produced in the sporophyte by meiosis. A spore can divide by mitosis to develop into a multicellular haploid individual, the gametophyte, without fusing with another cell. (2) In fungi, a haploid cell, produced either sexually or asexually, that produces mycelium after germination.  Bryophyte – An informal name for a moss, liverwort, or hornwort; a nonvascular plan that lives on land but lack some of the terrestrial adaptations of vascular plants. Examples of these are: Irish moss, reindeer moss, club mosses, and Spanish moss. 7. Plants that are vascular have an extensive system of vascular tissue, cells joined into tubes that transport water and nutrients throughout the pant body. Most plants have a complex vascular tissue system. Two types of vascular tissue Xylem and Phloem: Xylem – conducts most of the water and minerals. The xylem of most vascular plants includes tracheids, tube-shaped cells that carry water and minerals up from roots. The water-conducting cells in vascular plants are lignified; that is, their cell walls are strengthened by the polymer lignin. Phloem – has cells arranged into tubes that distribute sugars, amino acids, and other organic products. Roots – are organs that absorb water and nutrients from the soil. Roots also anchor vascular plants. Hence allowing the shoot system to grow taller.

Leaves – increase the surface area of the plant body and serve as the primary photosynthetic organ of vascular plants. All of the lycophytes have Microphyll leaves: small, usually spine-shaped leaves supported by a single strand of vascular tissue. Almost all other vascular plans have Megaphyll leaves: leave with highly branched vascular systems; a few species have reduced leave that appear to have evolved from megaphylls. Sporophylls – are modified leaves that bear sporangia. Sporophylls vary greatly in structure. In many lycophytes and in most gymnosperms, groups of sporophylls form cone-like structures called strobili. Most seedless vascular plants are homosporous: they have one type of sporangium that produces one type of spore, which typically develops into a bisexual gametophyte. In contrast, a heterosporous species has two types of sporangia and produces two kinds of spores: Megasporangia on megasporophylls produce megaspores, which develop into female gametophytes; microsporangia on micrisporophylls produce microspores, which develop into male gametophytes. All seed plants and a few seedless vascular plans are hetersporous. Lec 13 1. The four derived traits of seed plants include:  Reduced Gametophyte-Tiny gametophytes can develop from spore retained within the sporangia of the parental sporophyte. This arrangement protects the delicate female (eggcontaining) gametophytes from environment stresses. The moist reproductive tissues of the sporophyte shield the gametophytes from UV radiation and protect against drying out. This relationship also enables the dependent gametophytes to obtain nutrients from the sporophyte.  Heterospory-At some point, seed plants or their ancestors became heterosporous: Megasporangia produce mega spores that give rise to female gametophytes, and microsporangia produce microspores that give rise to male gametophytes. Each megasporangium has a single functional megaspore, whereas each microsporangium contains vast numbers of microspores. (Mega – 1, Micro – thousands)  Ovule-The whole structure-megasporangium, megaspore, and their integument(s) One integument in gymnosperms, and two integuments in angiosperms.  Pollen-A microspore develops into a pollen grain that consists of a male gametophyte enclosed within the pollen wall. The tough pollen wall, which contains the polymer sporopllenin, protects a pollen grain as it is transport from the parent by natural means. The transfer of pollen to the part of a seed plant that contains the ovules is called pollination. If a pollen grain germinates (begins growing), it gives rise to a pollen tube that discharges sperm into the female gametophyte within the ovule.  Seeds-If a sperm fertilizes an egg of a seed plant, the zygote grows into a sporophyte embryo. The whole ovule develops into a seed: The embryo, along with a food supply, packaged within a protective coat derived from integument(s). 2. An Angiosperm is a flowering plant, which forms seeds inside a protective chamber called an ovary. In angiosperms the male parts include anthers + filaments = stamens, and they produce pollen. While the female parts are the stigma + style + ovary, and they produce ovules. The petals attract pollinator, and these are modified leaves. Whereas, a Gymnosperm is a vascular plant that bears naked seedsseeds not enclosed in specialized chambers. The 4 main groups of gymnosperms are: Ginkophyta, Cyacadophyta, Gnetophyta, Coniferphyta.

3. Pollination can occur depending on the sperms produced. In seedless plants there is a flagellated sperm; it requires some type of water film or substrate to reach the eggs. This distance rarely exceeds a few centimeters. In seed plants a sperm-producing male gametophyte inside a pollen grain can be carried long distances by wind or by animals, eliminating the dependence on water for sperm transport. The sperm of seed plants also do not require motility because sperm are carried directly to the eggs by pollen tubes. 4. A fruit typically consist of a mature ovary, although it can include other flower parts as well. As seeds develop from ovules after fertilization, the wall of the ovary thickens. Fruits protect dormant seeds and aid in their dispersal. Mature fruits can be either fleshy or dry. Oranges, plums, and grapes are examples of fleshy fruits, in which the wall of the ovary becomes soft during ripening. Dry fruits include beans, nuts, and grains. 5. Monocots have 1 cotyledon and Eudicots have 2 cotyledon. A cotyledon is a rudimentary leave of plant embryo in arrested development. Monocots have parallel leaf veins (e.g. grass), and Eudicots have netlike veins (e.g. oak leaf). Lec 14/15 1. Animals are multicellular heterotrophic (internal digestion) eukaryotes. They have unique tissues, such as muscle and nervous tissue (in all except sponges), they lack rigid cell walls (unlike plants and fungi), structural support is provided by extracellular proteins, they are motile in at least some part of the life cycle, and their embryos pass thorough an early ‘blastula’ stage. 2. Gradual development can be related to a human, an animal that develops into adults through transient stages of maturation. Non-gradual development occurs when there is metamorphosis, this occurs when a developmental transformation turns the animal into a juvenile, which resembles an adult but is not yet sexually mature (e.g. Frog). 3. All eukaryotes have genes that regulate the expression of other genes, and many of these regulatory genes contain common sets of DNA sequences called homeoboxes. Hox genes play important roles in development of animal embryos, controlling the expression of dozens or even hundreds of other genes that influence animal morphology. 4. The first complex animals to arise were Ediacaran fauna, roughly 610-550 MYA. They were a diverse fauna which are now extinct. Examples of Ediacaran fossils show radial or bilateral symmetry. 5. There are two types of symmetry. Radial symmetry – a radial animal does not have a left side and a right side. Any imaginary slice through the central axis divides the animal into mirror images. Bilateral symmetry – a bilateral animal has a left and a right side. Only one imaginary cut divides the animal into mirror-image halves. Thus, bilateral animals have a dorsal (top) side, a ventral (bottom) side as well as an anterior (front) and a posterior (back). Many bilaterally symmetrical animals have sensory equipment concentrated at their anterior end, including a central nervous system (“brain”) in the head-an evolutionary trend called cephalization.

6. Animal body plans also vary according to the organization of the animal’s tissues. True tissues are collection of specialized cells isolated from other tissues by membranous layers. Ectoderm, the germ layer covering the surface of the embryo, gives rise to the outer covering of the animal and, in some phyla, the CNS. Endoderm, the innermost germ layer, lines the developing digestive tube or archenteron, and gives rise to the lining of the digestive tract. Animals that only have these two germ layers are said to be diploblastic, these include cnidarians as well as comb jellies. All bilaterally symmetrical animals have a third germ layer, called the mesoderm, between the ectoderm and endoderm. Thus, animals with bilateral symmetry are also said to be triploblastic. These include flatworms, arthropods, and vertebrates. 7. Most triploblastic animals possess a body cavity, a fluid- or air-filled space separating the digestive tract from the outer body wall. This body is also known as a coelom. A so-called “true” coelom forms from tissue derived from the mesoderm. Animals that possess true coelom are known as coelomates. Some triploblastic animals have a body cavity that is formed from mesoderm and endoderm, such a cavity is called a “pseudocoelom,” and animals that have on are pseudocoelomates. Finally, some triploblastic animals lack a body cavity altogether, they are known as acoelomates. 8. Protostome development – in animals, a developmental mode distinguished by the development of the mouth from the blastospore; often also characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split. Deuterostome development – in animals, a developmental mode distinguished by the development of the anus from the blastospore; often also characterized by radial cleavage and by the body cavity forming as outpockets of mesodermal tissue. 9. Metazoan consists of the following clades: Eumetazoa, “Proifera”, Bilateria, Deuterostomia, Lophotrochozo (Platyhelminthes, Rotifera, Ectoprocta, Brachiopoda, Mollusca, Annelida), Ecdysozo (Nematoda, Arthropoda). 10. Features of Phyla, refer to printed cheat sheet. Lec 16/17 1. Chordates are tiploblastic bilateria animals, that are coelomates and deuterostomes. The four main characteristics of chordates are, these are only displayed during the larval stage:  Notochord  Dorsal, hollow nerve chord  Pharyngeal slits  Muscular post-anal tail

2. ENDOTHERMS: Animals that generate body heat by metabolism. ECTOTHERMS: Animals that derive body heat from the environment.

3. Monotremes:  Only mammals to lay eggs  Produce milk, no nipples  Platypus Echidnas  Only ones to possess electroreception Marsupials:  Live birth  Milk from nipples  Rudimentary placenta, then pouch  Most found-Austalasia and South America Eutherians:  Ecologically most successful mammals  Complex placenta Dr. Klowden Unit 3-4 Ch. 40 1. Anatomy – Gross vs. Miroscropic (histology) 2. Physiology – The physical and chemical processes of an organism (biological function) and their study. 3. Form determines function by the “body plan.” Such examples may be the shape of a bird beak determines what the bird can eat or how it obtained foods. Or the wings and body lines of a bird can also determine what and how it eats. The shape of a bird’s foot can also determine how it searches or holds its food. 4. The 2 constraints on form and function are Evolutionary history & Physical laws, these place limits on form. 5. Smaller organisms have greater SA/V when compared to a larger animal’s SA/V, so they may lose heat, water faster. This also applies to cells, a larger cell has more difficulty moving substances in and out, and thus cell size is limited. Cells may lose water, or nutrients faster. 6. Cells > Tissues > Organs > Organ System. 7. Epithelial Tissue Main functions: A. Protection (mechanical damage, chemical damage, desiccation, infection, cleaning) B. Metabolic (absorption, secretion (glands)) Classified based on: 1. # of layers / simple vs. stratified 2. cell shape: 3. Specialization (ciliated, glandular, keratinized) Connective Tissue Types: 6 very different types General Morphology: Few & loosely associated cells (vs. epithelial or muscle w/ tightly associated cells) Abundant Extracellular Matrix produced by cells (2 primary components that differ in type and proportion in different connective tissues: A. ground substance (can be solid, gelatinous or liquid). B. fibers (3 types: collagenous (collagen), elastic (elastin), reticular (collagen but branched).

6 types of connective tissues  Loose CT    Fibrous    Cartilage   Bone    Adipose    Blood 

w/ all 3 fiber types Holds skin & most other organs in place Mainly collagen fibers Tendons and ligaments Collagen fibers in an abundant rubbery ECM both which are secreted by cells (chondrocytes) Collagen fibers in an abundant solid ECM both which are secreted by cells (osteocytes) Mainly large storage cells Cushions, insulates and stores fuel Various cell types in a liquid ECM

Muscle Tissue Types: 3 main types Morphology: Elongated cells (aka fibers)Unbranched or branched Single or multiple nuclei Function: Movement & Contract due to nerve signals Muscle tissue + connective tissue + nerves + blood vessels = an organ called a “muscle” 3 types of muscle tissue: A. Skeletal • Long, wide, parallel cells • Multiple nuclei located on edges • Striated • Voluntary - Location & function? • Attached to bones by tendons • Primarily used for movement B. Smooth • Small tapered cells • 1 nucleus • Not striated; • Involuntary - Location & function In walls of blood vessels, digestive tract, urinary bladder, reproductive tract, aids in digestion, circulation, reproduction C. Cardiac • Long, branched cells • 1 nucleus • Striated • involuntary • Intercalated disks between cells- faster communication btwn cells

Nervous Tissue Morphology 2 general classes of cells: Neurons - Transmit electrical signals Morphology Cell body: Axon – carries signal away from cell body toward another neuron, muscle or gland Dendrites – carries signal towards cell body Glia (singular = glial) Various types which function in:  Anchoring neurons  Providing nutrients for neurons  Removing dead cells  Form myelin sheath (increases transmission speed)  10x more abundant than neurons Function: Sense stimuli Transmit signals btwn body parts Coordination and Control Nervous system: Transmit signals btwn specific locations Better for rapid response (e.g. Locomotion and behavior) Endocrine system: Transmit molecules via the blood stream Better for gradual changes that affect the entire body (e.g. growth, development, reproduction, digestion etc.) Ch. 41 1. Carbon and Nitrogen needed to synthesize organic molecules and is obtained from the diet. Carbon comes from  Carbohydrates  Fats  Proteins Nitrogen comes from  Amino acids  Fatty acids  Vitamins  Minerals 2. Essential nutrients are required by the cells and cannot be synthesized from dietary organic molecules, and must be obtained from dietary sources. 4 classes of essential nutrients:  Amino acids  Fatty acids  Vitamins  Minerals

3. Amino Acids: Animals require 20 amino acids for protein synthesis. Animals can synthesize ~ ½ from molecules in diet. Thus ~ ½ are essential (i.e. must be obtained from the diet). 4. Fatty Acids: Acids produced when fats are broken down. There are saturated and unsaturated. They are used to produce some membrane phospholipids and for hormone production (e.g. blood pressure, immune response, inflammation response). Animals can synthesize all but 2 needed FAs linoleic and alpha-linolenic acids. Deficiencies in fatty acids are rare. 5. Vitamins: Organic molecules required in the diet in small amounts. Required – thus by definition all vitamins are essential (i.e. can’t be synthesized or synthesized in insufficient amounts). Needed in small amounts - vs. AAs and FAs which are needed in greater amounts Functions:  Coenzymes or precursors for coenzymes (bind to enzymes increasing their activity)  Hormone-like functions (e.g. regulate mineral metabolism, cell growth/ differentiation)  Antioxidants (reduce oxidation reactions that can damage cells)  Different species have different vitamins (e.g. Vitamin C only needed in apes, monkeys, bats, guinea pigs and a few others). 13 known vitamins in humans Humans can produce a few if conditions are right (but not enough to satisfy requirements):  Vitamin K and B7: Produced by intestinal microorganisms  Vitamin D: Produce w/ aid of UV light in skin  Vitamin A: from ingested beta-carotine 9 water-soluble, need regular replacement in body 4 fat-soluble (Vitamin A (retinol), Vitamin D, Vitamin E (tocopherol), Vitamin K (phylloquinone))., stored in the liver and fatty tissues, and are eliminated much more slowly than water-soluble vitamins. Overconsumption can cause health problems 6. Minerals: Inorganic chemical elements required by living organisms in small amounts vs. carbon (organic), hydrogen, nitrogen and oxygen (inorganic) Functions:  Coenzymes  Operation of nerves and muscles  Building of structures and molecules (e.g. bones, ATP, nucleic acids)  Osmotic balance (e.g. Na, K, Cl) All must be obtained in diet (i.e. none can be synthesized) 7. 4 Stages of food processing  Ingestion - the act of eating  Digestion - breaking food down into molecules small enough to absorb - Mechanical - Chemical  Absorption - uptake of nutrients by body cells  Elimination - passage of undigested material out of the digestive tract

8. Types of Ingestion: Stage 1: Ingestion:  Suspension (filter) feeders (Aquatic animals that sift small food particles from the water)  Substrate (Deposit) feeder (An animal that ingests partially decayed organic materials along with substrate) e.g. Earthworms and sand dollar  Fluid feeder (Suck nutrient-rich fluid from a living host)  Bulk feeder (Eat relatively large pieces of food) 9. Intracellular vs Extracellular  Phylum: Porifera - Intracellular only  Phyla: Cnidaria & Platyhelminthes - Mostly extracellular in the gastrovascular cavity but also intracellular. 10. Stage 2: Digestion - Occurs via both mechanical and chemical processes Mechanical – in mouth and stomach Chemical – in mouth, stomach and small intestine Mechanical digestion begins in the mouth Mastication: Grinding of bolus by teeth in mouth Mechanical digestion continues in the stomach Chemical digestion Occurs in the mouth, stomach and small intestine 1. Initiated by 4 general classes of enzymes  Carbohydrases (mouth, stomach, lumen & epithelium small intestine) – Carbohydrates  Proteases (stomach, lumen & epithelium small intestine) – Proteins  Nucleases (lumen and epithelium small intestine) - Nucleic acid  Lipases (lumen of small instestine) - Fats 2. Other chemicals  HCl – in stomach  Bile salts – in small intestine ***Do not need to know the names of specific enzymes in each class but should know the 4 general classes and where each occur as outlined in Table 41.13*** Chemical digestion begins in the mouth Salivary amylase is a carbohydrase produced by the salivary glands that breaks down (hydrolyzes) the carbohydrate starch Chemical digestion in the stomach, 3 layers of smooth muscles running in different directions mix food, so that all surfaces are exposed to digestive chemicals. Gastric glands in stomach have 3 types of epithelial cells that aid digestion Each gastric pits on interior epithelium of stomach is the entrance into a gastric gland Epithelial cells of gastric gland have 3 cell types that secrete different substances:  Mucus cells - mucus  Chief Cells - pepsinogen  Parietal Cells - H+ and Cl-

Chemical digestion in the stomach Pepsin and HCl are formed in the lumen of the gastric gland  Pepsinogen, H+ and Cl- secreted by chief and parietal cells of gastric gland  H+ and Cl- combine to form HCl in the lumen of the gastric gland  HCl converts pepsinogen to the enzyme pepsin in the lumen of the gastric gland  Pepsin converts (activates) more pepsinogen to pepsin (i,.e. positive feedback loop) 11. Absorption in the small intestine mainly in jejunum and some in ileum Villi = fingerlike projections of intestinal wall Microvilli = projections of cell membranes Most nutrients enter circulatory system Some fats enter lymphatic system Absorption in the large intestine  Absorption of water  Absorption of vitamins (biotin, K, B7) created by bacteria in caecum Ch. 42 1. Circulatory System:  Transport system that connects “organs of exchange” w/ entire body  Allows all cells to exchange w/ the environment  Allows communication between different organs and organ systems  Constraint: Physical Laws  All cells must exchange materials with the environment.  O2, CO2, H2O, NH3, nutrients  Direct exchange w/ environment NOT possible for most cells 2. Gastrovascular cavity Functions in:  Digestion  Distribution of substances throughout entire body (i.e. “circulation”)  Nutrients need to diffuse through 1 cell layer Some organisms have more elaborate GVCs  Planarian: highly branched GVC and flat body  Jellies: Elaborate GVC w/ ciliated cells to move substances  Radial canal  Circular canal  No Heart, but have ciliated cells 3. Complex animals 3 Components:  Fluid  Tubes  Pump

4. Open System vs Closed System: Closed System:  Blood never leaves tubes and moves in one direction;  O2 rich blood doesn’t mix w/ O2 poor blood nor waste (NH3)  O2/nutrients/NH3 moves btwn cells & blood via interstitial fluids  Occurs in some invertebrates & ALL vertebrates. Open System:  Tubes open-ended;  Tissues/organs in hemocoel bathe in hemolymph (Hemolymph: analogous to blood + interstitial fluid)  O2 rich and poor hemolymph and waste (NH3) mix  Occurs in arthropods & mollusks Open circulatory system  Lower pressure so requires less energy Closed circulatory system  Higher pressure allows distant delivery (i.e. bigger bodies)  Allows for a design in which oxygenated and deoxygenated blood is not mixed  Consists of blood vessels and a 2 to 4 chambered heart  Blood vessels Heart → Arteries → Arterioles → Capillaries → Venules → Veins → Heart  Heart chambers  Atria (1-2)  Ventricles (1-2) Fishes:  2-chambers (1A, 1V)  Single circulation Amphibians:  3-chambers (2A, 1V)  Some O2 rich/poor blood mixes but ridge keeps most separate  When diving, O2 poor blood diverted from lungs but not skin (i.e. cutaneous respiration)  Double circulation Reptiles (except birds)Turtles, snakes, lizards:  3-chambers (2A, 1V)  Partial septum in ventricle keeps almost all O2 rich/poor blood separate Crocs:  4-chambers (2A, 2V)  TWO systemic aortas in turtles, snakes, lizards and crocodilians  When diving, O2 poor blood diverted from lungs in some reptiles  Double circulation Mammals:  4-chambers (2A, 2V)  Double circulation

5. Mammalian Circulation: 1. R atrium to R ventricle 2. to pulmonary arteries 3. to capillaries of lungs 4. to pulmonary vein 5. to L atrium to L venticle 6. to aorta 7. to coronary arteries of heart and arteries/ capillaries of the head, limbs and organs 8. to anterior and posterior vena cava 9. to R atrium 6. Heart Pumping: Cardiac cycle - The sequence of contraction and relaxation that makes up the heartbeat:  Atrial and ventricular diastole (=relaxation)  Atrial systole (=contraction); ventricular diastole (=relaxation)  Ventricular systole (=contraction); atrial diastole (=relaxation) Cardiac output - Blood volume pumped/ minute depends on:  Heart rate - beats/ minute  Stroke volume - Amount of blood pumped from ventricle per contraction Control of heart rhythm:  Sinoatrial node generates signal causing atria to contract  Signals delayed at atrioventricular node  Signals pass to heart apex  Signals spreads throughout ventricles Sinoatrial node (SA):  Sets contraction rate and timing  Affected by physiological cues (e.g. hormones, temp., exercise)  Intercalated discs between cardiac muscle cells speed transmission of signal 7. Vessel Architecture: VEINS > TOWARDS HEART, ARTERIES>AWAY FROM HEART Veins vs Arteries structure both with 3 tissue layers:  Outer connective tissue (thicker in arteries)  Middle smooth muscle (thicker in arteries)  Inner epithelim (endothelium) (a smooth simple squamous epithelium, similar in arteries and veins)  Lumen (larger in veins)  Valves (veins only) Capillary structure 1 tissue layer:  Inner endothelium  Outer basement membrane  ECM (fibers) secreted by epithelial cells  Lumen – thickness of RBCs

8. Blood flow in arteries due to:  heart pumping  contraction of smooth muscle  recoil of elastic connective tissue Blood flow in veins due to:  contraction of smooth muscle  contraction of skeletal muscle  expansion due to pressure change veins near heart only) 9. Capillary exchange: Osmotic pressure (OP) and blood pressure (BP) affect fluid exchange btwn capillaries and interstitial fluid Venous end of capillary bed:  BP low (far from heart).  OP high due to large proteins & RBCs in blood making [solute] higher than interstitial fluids.  Since OP>BP, interstitial fluid (H2O) + waste (CO2, NH3) flow from tissues into capillary due to osmosis Arteriole end of capillary bed:  BP>OP  Net flow of H2O, nutrients, O2 out of capillary into tissue 10. Blood Composition: Blood - cells suspended in liquid called plasma Plasma (55% of blood)  Water (90% of plasma)- Solvent for carrying other substances  Ions - Osmotic balance, pH buffering, and regulation of membrane permeability  Proteins - Osmotic balance, pH buffering, clotting, immune defense  Transported substances – Nutrients, waste products of metabolism, respiratory gases (O2 and CO2), hormones Cells (45% of blood)  Erythrocytes (red blood cells) - Transport oxygen and help transport carbon dioxide  Leukocytes (white blood cells)(Basophil, eosinophil etc…)- Defense and immunity  Platelets - Blood clotting 11. Blood Clotting: 1. Endothelium of blood vessel is damaged, exposing connective tissue (CT); platelets adhere to collagen fibers of CT and release a substance that makes nearby platelets sticky 2. Platelets form plug 3. If severe, plug reinforced by fibrin. To form fibrin: 1. Clotting factors released from platelets and damaged cells mix with clotting factors in the plasma. 2. Mixture causes the protein prothrombin to be converted (activates) to thrombin (an enzyme) 3. Thrombin converts fibrinogen (a soluble protein) into fibrin (insoluble)

Ch. 43 1. Immune System - A collection of biological structures (cells, tissues, and organs) and processes within an organism that help protects against disease by removing pathogens and abnormal cells 2. Pathogen - Disease causing microorganisms, viruses and fungi. 3. The Immune System: Innate Immunity  1° defense  Nonspecific  Fast  External innate defenses - try to prevent entry of pathogen  Internal innate defenses - fight pathogen once inside  Innate immunity occurs in plants, Invertebrates, Vertebrates Acquired Immunity  2° defense  Specific  Slower  Cell-mediated response - cytotoxic cells (lymphocytes)  Humoral response - antibodies in body fluids  Acquired immunity occurs only in jawed Vertebrates 4. Innate Immunity Internal Defenses:  Phagocytosis  Antimicrobial peptides  Inflammation - Only in vertebrates  Natural Killer (NK) cells - Only in vertebrates White blood cell (WBC) (aka lymphocyte) is a brood name for 5-7 types of cells of the immune system;  Pluripotent stem cell → (Multipotent) Hematopoietic stem cell  Lymphoid stem cell → Lymphocytes (B and T) NK cell**  Myeloid stem cell → RBCs, platelets, & several WBCs (baso-, eosino- & neutrophils, monocytes (which become macrophages**, mast cells**)  WBCs have special transmembrane proteins (toll-like receptors (TLR)) that bind to certain molecules on a pathogen’s surfaces;  This recognition of the pathogen initiates internal defenses (phagocytosis, antimicrobial peptides, inflammation, NK cells)  Some TLRs are within the WBC outer membrane, others are in membranes of vesicles;  TLRs are nonspecific, binding to cell surface molecules which don’t occur in animals cells but which are common to a group of pathogens (e.g. bacteria in general, not a specific bacteria type).  Different kinds of WBCs have different TLRs  There are 13 types in humans.

Phagocytosis  Primarily by 2 types of WBCs: neutophils and macrophages (monocytes)  Vacuoles w/ pathogens bind to lysosomes containing toxic gasses (e.g. NO) and enzymes (e.g. lysozyme)  Some macrophages roam through the vascular & lymphatic systems, others wait in various tissues and organs (especially lymphatic tissues) Antimicrobial peptides  Proteins (not cells!) that attack microbes or impede their reproduction  Usually recognize brood groups of pathogens (e.g. gram + or – bacteria, fungi)  May already be in the tissue (constitutive) or produced by macrophages, epithelial cells or infected cells upon recognition of a pathogen (induced) Kill cells in a variety of ways  Integrate w/ membranes causing a hole and/or altering membrane function  Integrate w/ intracellular molecules altering their function Inflammation  Mast cells (a type of WBC in connective tissue) produce histamine (a nitrogenous chemical)  Histamine increases blood vessel permeability allowing antimicrobial peptides to enter tissue  Macrophages (another WBC) produce prostaglandins which attract other phagocytic WBCs Natural Killer (NK) Cells  Kill cancerous or infected cells by releasing chemicals  Does not cause lysis (which would spread cell contents)  Do not phagocytize  Are a 3rd type of lymphocyte produced by lymphoid stem cells 5. Acquired Immunity: Lymphocytes  T- Cells - Mature in thymus  B- Cells - Mature in bone marrow Both are activated by:  Cytokines from macrophages  Antigens (a foreign molecule)(e.g. pollen or bacteria) Cytokine - various proteins produced by various immune cells that help recruit and activate lymphocytes 2 types of T- cells  Helper T-cells - Activate lymphocytes (Both B and T)(cheerleader)  Cytotoxic T-cells - Disable infected cells 1 type of B- cell - Secrete antibodies Lymphocytes are very specific - Different T- or B-cells for each different type of pathogen

6. Antigen Receptors  Transmembrane protein in B and T cells that recognize foreign molecules (antigens)  Are Y shaped in B-cells  Are straight in T-cells  Each B and T cell has ~100,000 identical antigen receptors  Thus, each T- or B-cell can only recognize 1 type of antigen Antigen Receptor Structure  All antigen receptors have 2 halves bound together  All antigen receptors have both a constant and variable region  Constant: Different B-cells have similar constant regions as do different T-cells.  Variable: Dfrnt lymphocytes have dfrnt variable regions, & thus recognizes dfrnt antigens  1,000,000 different B-cell antigen receptors  10,000,000 different T-cell receptors  Thus T-cells recognize many more types of antigens than B-cells 7. Antibodies (aka Immunoglobulins) - Secreted B-cell receptors (i.e. NOT attached to B-cell membrane) Role of B-cell Antibodies:  Antibodies inactivate antigens via several methods  Neutralization - Block all accessible surfaces of antigen  Opsonization - Make it easier for macrophages to phagocytose antigen  Opsonization furthered by linking molecules together  Agglutination – Linking of insoluble molecules  Precipitation – Linking of soluble molecules Antibodies inactivate antigens via several methods  Activation of complement system  Binding of antibodies to an antigen activates the complement system (a series of protein activations that constructs an attack complex to bore a hole in the antigen leading to lysis) 8. INFECTED body cells use special molecules (MHC I) to present antigen fragments to CYTOTOXIC Tcells. “Major Histocompatibility Complex” I (MHC I) molecules  Occur in almost all body cells  Present intracellular antigen fragments from infected cell  Cytotoxic T-cell binds to MHC I/ antigen fragment complex  Binding activates the cytotoxic T-cell causing it to kill the infected cell PHAGOCYTIC cells use different molecules (MHC II) to present antigen fragments to HELPER T-cells “Major Histocompatibility Complex” II (MHC II) molecules  Occur only on phagocytic cells: macrophages and B-cells (+ a few others)  Phagocytose antigen & use MHC II to present fragments on its surface.  Macrophage presents to helper T-cell which activates helper T-cell  Activated helper T-cell binds to B-cell presenting same antigen  Activated helper T-cell releases cytokines activating the B-cell

9. Effector vs Memory Cells Effector cells Plasma cell (antibody secreting B-cell) Active cytotoxic T cell Helper T-cell  Short lived  Numerous once activated  Attack antigens Memory cells Memory B-cell Memory helper T cell Memory cytotoxic T cell  Live a long time (10-20 yrs)  Less numerous than effector cells  Activate effector cells & give riseto effector and memory cells Memory cells result in immunological memory 10. Activated by: B cell Helper T cell Cytotoxic T cell 1. binding to antigen 2. cytokines from activated helper T cell 1. cytokines from MHC II presenting phagocytic cell 2. its own cytokines 1. interaction w/ MHC I presenting infected cell 2. cytokines from activated helper T cells

Ch. 44 1. Excretory system - The organs and processes which regulate water level and ion concentrations (osmoregulation) and remove nitrogenous waste (excretion). 2. Osmosis - Differences in solute concentrations on 2 sides of a selectively permeable membrane result in movement of water from areas of lower concentration to higher concentration.  Selectively permeable membrane (SPM) prevents the movement of solutes via diffusion, so H 2O must move instead.  Net water flow  Hypoosmotic (hypotonic)  Hyperosmotic (hypertonic)  Isoosmotic (isotonic) = No net water flow Hyperosmotic, hypoosmotic and isoosmotic are all comparisons of the 2 sides of the selectively permeable membrane

3. Osmoregulation - Due to osmosis, water enters (freshwater) or leaves (saltwater) a fish. To compensate for H2O gains or losses it it regulates (+/-) its excretion & drinking Saltwater fish hypotonic (compared to the H2O it’s swimming in) so loses H2O  H2O loss due to osmosis (across gills and skin)  Must gain H2O. Gets some from food but not enough so actively drinks  But saltwater contains many ions (salt etc) so must excrete excess  Excretes most in highly concentrated urine (i.e. solutes >> H2O) and rest actively (uses energy) pumped out across gill membranes. Freshwater fish hypertonic (compared to the H2O it’s swimming in) so gains H2O  H2O gain due to osmosis (across gills and skin)and some more in food  Must lose H2O, so does NOT drink!, but instead excretes a lot of H2O in highly dilute (H2O >> solutes) urine.  Also, loss of ions due to diffusion across gills  Uptakes some ions in food and actively uptakes rest across gill membranes Anadromous fish are born in freshwater live in saltwater and return to freshwater to breed (e.g. salmon, sturgeon, lamprey, shad, herring, and striped bass) Catadromous fish live in freshwater and enter saltwater to breed (e.g. many eels) 4. Nitrogenous Wastes - Byproducts of metabolism converted to 3 nitrogenous forms in the liver Ammonia – Very toxic  Must be diluted to transport in blood for excretion across gills or will poison animal  Thus only occurs in aquatic animals  Cannot be stored  Least energy to produce as compared to urea and uric acid  Produced by most aquatic animals including invertebrates and most bony fish Urea - Less toxic than ammonia (100,000x less)  Conserves water since doesn’t need to be diluted  More energy to produce than ammonia but less than uric acid  Can occur in [higher] in blood for excretion by kidney or stored in bladder  Produced by mammals, most amphibians, sharks and some bony fish Uric acid - Least toxic  Conserves more water than urea  Most energy to produce as compared to ammonia and urea  Can occur in [higher] in blood for excretion by kidney (not stored since no bladder)  Good for storage in amniotic egg  Produced by reptiles (including birds), insects and land snails

5. Tubular Theme in Excretory systems -All excretory systems are made of many tubules which vary in size, shape and function depending on the organism Variation in Tubular Theme Flatworms use Protonephridia for osmoregulation  Filter interstitial fluid  Reabsorb needed nutrients back into interstitial fluids  Excrete unneeded substances via pores in body wall o mainly H2O (osmoregulation) o i.e. not used for excretion o (but also NH3 in parasitic flatworms) Most Annelids use Metanephridia for osmoregulation & excretion • Special cells (podocytes) compose epithelium of blood vessels within the coelom • unselectively filter H2O, many nutrients and waste products into coelomic fluid • Metanephridia are open-ended funnels within the coelomic fluid that: 1. Reabsorb H2O & needed nutrients from coelomic fluids into surrounding blood vessels 2. Excrete unneeded substances via pores in body wall • H2O • NH3 • Metanephridia • reabsorb and excrete but do NOT filter wastes (podocytes filter) • are involved in both osmoregulation and excretion Insects use Malpighian Tubules for osmoregulation and excretion  Outfoldings of midgut that extend into hemocoel  Malpighian tubule epithelial cells: o Absorb salt from hemolymph and secrete it into lumen of tubule o H2O follows into lumen due to osmosis o NH3 follows into lumen due to diffusion  Filtered H2O and NH3 empty into midgut mixing w/ digesting food  In hindgut (rectum) solutes pumped back into hemolymph o Reabsorption of H2O follows via osmosis  Dry fecal pellet containing undigested food and uric acid eliminated Kidney; Urinary system = Renal artery/vein, kidney, ureter, bladder, urethra 6. Kidney Function  Kidneys filter total blood volume 300 times per day  Produces 180 L of filtrate  Reaborbs 95% of filtrate  Excretes 1.5L Comprised of 3 parts – Renal cortex, renal medulla, renal pelvis Nephron:  basic functional unit of kidney  ~ 1,000,000 nephrons per human kidney  Most nephrons only in cortex (cortical nephrons)  ~ 15% of nephrons have long tubes that stretch down into medulla (juxtamedullary nephrons) juxtamedullary nephrons critical to H2O reabsorption

Nephron Structure 1. Bowman’s capsule (Surrounds glomerulus (ball of capillaries), Bowman’s capsule + glomerulus = renal corpuscle) 2. Proximal tubule 3. Loop of Henle (Descending limb + Ascending limb) 4. Distal tubule 5. Collecting duct – many nephrons share same collecting duct Nephron Function  Renal corpuscle = glomerulus + Bowman’s capsule  Special cells, podocytes, wrap around glomerulus capillaries and filter blood into bowman’s capsule  Filtrate includes H2O and all SMALL molecules in blood including NaCl, urea, glucose, vitamins, amino acids  Filtrate known as “pre-urine” since much processing yet to occur Proximal tubule Reabsorption: H2O, Na+, Cl-, vitamins etc. 1. Sodium (Na+) actively pumped out of PT to interstitial fluids 2. Chloride (Cl-) passively follows (due to opposite charge) 3. H2O follows via osmosis 4. Some nutrients passively follow: glucose, amino acids, potassium (K+) 5. Na+, Cl-, H2O, nutrients all reenter capillaries Loop of Henle: Descending Limb  Reabsorption of H2O  Permeable to H2O NOT NaCl or other solutes  H2O exits passively (osmosis) due to high NaCl concentration in surrounding tissues  Filtrate ion concentration increases as it proceeds along loop. Ascending limb  Permeable to Na+ & Cl- but NOT H2O, Na+ & Cl- exit  Thin portion – via diffusion due to higher NaCl concentration inside tubule than in surrounding tissues  Thick portion – via active transport due to similar NaCl concentration inside tubule than in surrounding tissue  Reabsorption of NaCl establishes osmotic gradient in surrounding tissues (i.e. around descending limb) Vasa Recta  Group of capillaries surrounding Loop of Hanle that returns H2O and NaCl from Loop of Henle back to blood Distal tubule Reabsorption  H2O  NaCl Excretion  K+ from surrounding tissues enters distal tubule for excretion Collecting duct  Reabsorption of NaCl and/ or H2O  Multiple nephrons drain into a common collecting duct which then enters ureter

Ch. 45 1. What is the Endocrine System? The glands and organs that secrete chemicals (hormones) into the circulatory system for delivery via the blood and lymph to affect the function of other organs, tissues and cells involved in a variety of functions such as: Growth, Reproduction, Development, Digestion/ Metabolism, Appetite control, Metabolic rate (O2 consumption), Osmoregulation, Immunity, Melanin production, Mood, Fight or flight response, Pain perception, Circadian rhythm, Dreams possibly. 2. Exocrine glands  Secrete products into ducts that lead to the external environment  Secretions are not used for communication btwn body parts thus are not hormones  Are NOT part of the endocrine system Endocrine glands  Secrete products directly into the circulatory system without ducts  Secretions ARE used for communication btwn body parts thus ARE hormones  ARE part of the endocrine system  Some organs contain endocrine cells or tissues. 3. Paracrine/ autocrine signaling & Immunity  Cytokines secreted by macrophage activates nearby helper T-cell  Cytokines secreted by helper T-cell activates B-cell and cytotoxic T-cell (paracrine) and itself (autocrine)  Infected body cells secrete cytokines which activate nearby NK cells (paracrine)  Natural Killer cells secrete chemicals killing nearby infected cell (paracrine)  Histamine secreted by mast cells increases nearby blood vessel permeability  Prostaglandins secreted by macrophages attract nearby phagocytic cells 4. Neurotransmitters  Local regulators that cross synapses Neurohormones  Released from specialized neurons (neurosecretory cells) of nervous system organs into the blood  e.g. Anterior pituitary releases prolactin into blood which acts on mammary gland to produce milk 5. Posterior Pituitary Gland  Stores and secretes 2 hormones made by hypothalamus  ADH - Antidiuretic Hormone  Oxytocin - reproduction  Hypothalamus neurosecretory cells deliver hormones to posterior pituitary  Hypothalamus stimulates post. pit. to release hormones via nervous signal

Posterior Pituitary and the Effect of ADH  Increased blood solute concentration (i.e. osmolarity) detected by osmoreceptor in hypothalmus (dehydration causes greater solute concentration, i.e. more solutes/ ml water)  Stimulates thirst and drinking which causes blood osmolarity to decrease.  Hypothalmus sends nerve impulse to posterior pituitary.  Post pit releases ADH into blood.  ADH goes to collecting duct in kidney and increases permeability to water.  Water moves out of collecting duct into blood, decreasing blood osmolarity. Posterior Pituitary & Reproduction Oxytocin stimulates smooth muscles in breasts (and uterus)  Suckling detected by hypothalamus which signals posterior pituitary  Post pit releases oxytocin into blood  Oxytocin acts on smooth muscles in breast  Muscles contract releasing milk Anterior Pituitary Gland  Synthesizes AND secretes hormones (vs Post pit which stores/secretes)  Controlled by hormones delivered directly from hypothalamus (vs. post pit which is controlled by nerve impulse from hypothalamus) 2 classes of hormones control hormone release from the ant. pituitary  Releasing hormones  Inhibiting hormones  Each hormone synthesized by the ant. pit. has 1 releasing and 1 inhibiting hormone that controls it.  Produces hormones with tropic and/or non-tropic effects  Tropic hormones regulate other endocrine organs  Non-tropic hormones directly stimulate target cells to induce effects  Some ant. pit. hormones have both tropic & non-tropic effects  Growth Hormone has both tropic and nontropic effects  Tropic Induces liver to release IGF-1 which regulates bone growth  Non-tropic Acts directly on muscles to stimulate growth 6. Thyroid  Absorbs and stores iodine (a mineral)  Produces and secretes T3, T4  Regulation of blood pressure, heart rate, digestion, reproduction From AA Tyrosine and iodine  T4→T3 in liver, kidney, spleen using selenium (a mineral) T4 more stable / T3 more active  Calcitonin Produced in C-cells of thyroid C-cells bind Ca2+ in blood Increased Ca2+ causes calcitonin release Inhibits uptake of Ca2+ from small intestine Inhibits Ca2+ release from bones  HyperthyroidismSweating, weight loss, high BP etc.  An example is Grave’s disease - Autoimmune disease Antibody binds to TSH receptor on anterior pituitary Causes too much T3/T4 to be made  Hypothyroidism Weight gain, lethargy, cold intolerance, etc.  Goiter - Low iodine leads to low T3/T4 Normally, increased T3/T4 in blood causes decreased TSH (neg feedback) but w/ goiter, lack of T3/T4 leads to high TSH since no neg feedback

7. The Pancreas is an endocrine and exocrine gland  Aids chemical digestion by producing/releasing bicarbonate & enzymes into duodenum  Produce/releases hormones that regulate blood glucose levels  Insulin decreases blood glucose level causes body cells & liver to uptake glucose & store it as glycogen  Glucagon increases blood glucose level, breaks down stored liver glycogen into glucose and releases to blood Diabetes – excess glucose in blood and urine Type I  low insulin production  Appears during childhood Type II  Insulin receptor on target body/liver cells malfunction so don’t uptake glucose  Usually occurs after age 40 but obesity lowers age Ch. 48 1. What is a Nervous system? The collection of organs, tissues and cells that coordinates records and distributes information by electrical and chemical signals between the brain and other parts of the body allowing response to external stimuli and control of other organ systems. 2. Most animals have nervous systems except sponges. 3. Nervous system comprised of 2 general cell types  Neurons - Transfer information via electrochemical energy  Glial Cells - Support cells for neurons 4. Neuron Structure Most neurons have three main parts: Dendrites  bring electrical stimuli from other neurons or sensory epithelial cells to the cell body.  several to many per neuron Cell body  receives stimuli from dendrites or other neurons and propagates to axon  synthesizes some neurotransmitters (or neurohormones)  contains nucleus and other cell organelles Axon  receives stimulus from cell body of neuron and propagates signal to synapse  only 1/ cell but distal end has several to many branches (thus each neuron can contact many other neurons)  synthesizes some neurotransmitters in synaptic terminals

5. The synapse is the narrow space between 2 cells.

6. 4 Functional Types of Neurons Sensory (afferent) – transmit info from external or internal sensors to the brain (or ganglia) Interneurons – Analyze and interpret sensory input  Found exclusively within the spinal cord and brain  Stimulated by sensory neurons, other interneurons or both  Hundreds or more types of interneurons  Have many more dendrites than other neuron types (~100k) Motor (efferent) – transmit signals to muscle and gland cells from the brain (or ganglia primarily stimulated by interneurons Neurosecretory – transmit chemicals into blood which act on distant targets 7. CNS vs PNS  Central Nervous System (CNS) = Brain + spinal cord  Peripheral Nervous System (PNS) = Cranial nerves + Spinal nerves + Ganglia (i.e. nerves only occur in the PNS) 8. Ganglion - A dense cluster of interconnected neuron cell bodies that, depending on the type, relay sensory (spinal ganglia) information to (afferent) or motor outputs from (efferent) spinal cord. vs. brain  Smaller/ less complex than vertebrate brain  Only contain neuron cell bodies not axons or dendrites  In PNS in vertebrates but in CNS in invertebrates  Insect's brain is 6 fused ganglia in head each controlling different parts/ activities 9. Cranial vs Spinal Nerves All are mixed nerves (afferent & efferent) except for optic nerve (afferent) Cranial nerves  Originate in the brain and serve head and neck  12 pairs in humans and most vertebrates Spinal nerves  Originate in the spine and serve body below head  31 pairs in humans ~ corresponding to vertebral column segments  Outside the vertebral column, each spinal nerve divides into various branches 10. Glial Cells  Occur only in CNS  Support Cells for neurons  Several types with different functions o Anchor neurons o Improve nutrient deliver to neurons o Remove dead neurons  Form myelin sheath around axons o Schwann Cells (PNS) o Oligodendrocytes (CNS)  Circulate cerebrospinal fluid  10-50x abundance of neurons

11. How a neuron works Membrane potential – difference in electrical charge (voltage) across a plasma membrane due to differential distribution of ions on each side of membrane Greater movement of ions across membrane in one or other direction generates electrical energy (voltage) Resting potential - membrane potential of a nontransmitting neuro (i.e. no ion movement in or out) -60 to -80 mV (millivolts) (inside has more - ions than outside or fewer + ions than outside) Depolarization = a change in a cell’s membrane potential  Occurs when the inside of the cell becomes less negative as compared to the outside due to Na+ ions moving in (i.e. goes from -60mv to 0mv)  Charge difference btwn inside/ outside facilitated by selectively permeable ion channels.  Active: Na+/K+ pump creates different Na+ concentrations and K+ concentrations inside and outside cell  Passive: More K+ channels so movement of K+ out > Na+ in  If movement was equal in both directions there would be no net energy Neuron Ion Channels Un-gated  Always open; passive ion diffusion Gated  Open & close to stimuli Voltage-gated ion channels (VGIC)  Open or close due to change in membrane potential  Stimulus opens Na+ channel and ions flow in making inside less negative (depolarization)  VGICs open in response to depolarization  Further depolarization causes more VGICs to open.  Rapid depolarization called “action potential” Ligand-gated channels  Open due to binding of chemical to ion channel (e.g. neurotransmitter)  Other less common channels respond to light, temp, pressure, stretch 12. Transmission of impulse 1. Resting state:  Gated Na+ and K+ channels closed  Membrane potential -60mv 2. Depolarization:  Stimulus opens some gated Na+ channels causing some VGISs to open  Membrane potential begins to increase (i.e. less negative) 3. Rising phase of Action Potential  Threshold reached (-50mv) and most gated Na+ channels open  Causes inside of cell to become + with respect to outside of cell 4. Falling phase of action potential  Most Na+ channels close and most K+ channels open  K+ flows out and membrane potential becomes negative again 5. Undershoot  All Na+ channels closed but some K+ channels still open  Membrane potential becomes more – than at rest (1 nucleus = a bundle of myofibrils  A muscle contains many bundles of muscle fibers A Skeletal Muscle is an organ Comprised of:  Bundles of muscle fibers (muscle tissue)  + fibrous/elastic connective tissues (btwn/around muscle fibers)  + blood vessels (connective/muscle/epithelial tissues)  + nerves (nervous tissue)  + lymph capillaries (epithelial tissue) 2. A muscle cell is a bundle of many myofibrils Myofibril morphology:  Chain of repeating subunits (sarcomeres) Each sarcomere contains:  Thin filaments made of actin (a protein)  Anchor to Z disk (a protein)  Thick filament made of myosin (a protein)  Attach to thin filaments  Alignment of Z-discs causes striations in skeletal muscles In smooth muscle Z-discs are not aligned so no striations  Myofibrils are not parallel as in skeletal muscle which allows contraction in multiple directions 3. Skeletal Muscle Contraction Contract via myosin microfilaments crawling along actin Changes in the conformation of the myosin head produce movement  ATP binds to myosin head of thick filament causing it to release from thin actin filament  ATP broken down into ADP + P which causes myosin head to pivot forward and attach to thin actin filament.  P released from myosin head causing it to pivot backwards (power stroke) advancing the myosin filament.  ADP released from myosin making a spot available for a new ATP molecule (which will cause the myosin head to release from the actin) Some myosin heads are pulling while others are extending 4. Troponin-tropomyosin protein complex regulate contraction and relaxation At Rest:  Myosin binding sites on thick actin filament blocked by tropomyosin (a protein) Contracting:  Ca2+ binds to troponin moving tropomyosin & unblocking myosin binding site on actin 5. Rigor mortis Upon Death:  Ca2+ released and muscles contract  ATP levels drop so myosin head can’t release to relax muscles

6. Sensory Receptors Cells and organs that respond to specific stimuli from outside or within body  Most sensory cells are afferent neurons or specialized epithelial cells  Physical or chemical stimuli cause a change in the membrane potential of the cell (via voltage, ligand and/or other types of gated ion channels)  If sensory receptor cell is a neuron, this results in an action potential  Other sensory receptor cells release neurotransmitters which lead to an action potential in an abutting neuron

7. 5 general types of Sensory Receptors Chemosensory  Taste cells and taste buds  Receptor cells  Supporting cells  Basel stem cells  5 tastants  Olifaction  Pheromones  Vomernasal organ Mechanosesnory  Stretchreceptors  Muscle Spindle  Motion sensing hairs  Hearing (insects vs verts)  Lateral Lines Electromagnetic  Pit organs  Mettallic particles in the heads of birds  Ampullae of Lorenzini  Simple eye cup  Compound eye  Single lens eye (details.. rods, cones, retinal, opsin) Thermosensory Pain

Ch. 35

1. Plant Tissues Each plant organ contains three tissue types: Dermal  Outer protective covering Vascular  Transport water, minerals, nutrients Ground  Photosynthesis, storage, support Morphology and/or relative location of each tissue differs in each organ 2. Plant Cells Primary cell wall  made of cellulose,  develops during growth of cell. Secondary cell wall  thicker than primary  develops after cell stops growing,  is internal to primary cell wall and adds strength.  Made of cellulose and lignin or other molecules  Occurrence and thickness of 2o cell wall varies among plants and cell types. 3. Some Cell Types occur in various tissues Parenchyma  Variety of functions Collenchyma  Flexible support Sclerenchyma  Rigid support These cell types can occur in any tissue (dermal, vascular, ground) but may vary in morphology and function in different tissues Parenchyma Cells  Most abundant cell type  Multiple functions involved in protection, synthesis and storage e.g. outer epidermis e.g. photosynthesis in leaves e.g. starch storage in roots  Usually have a large central vacuole  Thin 1o cell wall; most lack 2o walls  Can differentiate into other cell types Collenchyma Cells  Grouped in strands (often just below epidermis)  Give flexible support to young plant parts w/o restraining growth (e.g. celery “strings”)  Unevenly thickened 1o cell walls; No 2o walls Sclerenchyma Cells  Thick 2o cell walls w/lignin  Provide strong structural support in nongrowing parts  Often dead at maturity

2 specialized types: Sclereids  Shorter than fibers and irregular shapes  Very thick 2o wall w/ lots of lignin e.g. nutshells, seed coats, pear skin grittiness Fibers  long, slender, tapered cells  Grouped in threads e.g. hemp, flax 4. Stomata (singular = stoma)  Pores that occur in leaves and stems  Regulate H2O, gas and heat exchange  Lined by guard cells Stomata function:  Pump H+ out of guard cells causing negative membrane potential  Votage-gated K+ channels open and K+ flows in from neighboring cells  Negative ions (e.g. Cl-) are also brought in causing more K+ to flow in  Increased K+ & Cl- ion concentration causes H2O to flow in via osmosis  Cells swell & bow outward 5. Leaf Arrangement  Opposite: 2 leaves / node  Alternate: 1 leaf / node  Whorled: 3+ leaves / node Simple leaves do not have leaflets Compound leaves have leaflets arranged:  Pinnately Compound – leaflets extend on both sides of midrib from base to tip  Palmately Compound – leaflets extend from a single point ***NOTE*** If shown a plant diagram you should be able to categorize it as simple or compound, identify its venation (pinnate, palmate, parallel) and if compound, its leaflet arrangement (pinnate, palmate). 6. 3 overlapping zones: Zone of cell division  Mitosis in Root Apical Meristem Zone of elongation  push root tip down Zone of maturation  Differentiation into specific cells (tracheids, sieve, epidermal, guard…)

7. Meristems are areas of undifferentiated cells which generate differentiated cells for new organs Apical = > length (1o growth) Shoot AM  Apical bud - active  Axillary bud – most dormant Root AM  Zone of cell division – active  Pericycle - active Lateral = > width in woody plants (2o growth)  vascular cambium  cork cambium Ch. 51 1. Behavior – action carried out in response to a stimulus under control of the nervous system. Behavioral Ecology - study of ecological and evolutionary basis for animal behavior. 2. Innate Behavior - A genetically inherited, automatic, involuntary, unlearned and consistent response to a stimulus. 3 Types:  Reflex  Fixed Action patterns  Orientation behaviors Reflex: Simple, nearly instant innate movement in response to a stimulus. Most occur by direct connection of sensory & motor neurons in the spinal cord w/o input from the brain. Fixed Action Pattern Sequence of often species specific innate behaviors in response to an external cue (sign stimulus) and which once initiated continue to the end. Orientation Behaviors An innate behavior that alters movement in a specific way in response to an external cue 3 types:  Kinesis  Taxis  Migration Kinesis - Change in activity or turning rate in response to a stimulus Taxis - Oriented movement toward (+) or away (-) from stimulus Rheotaxis: orient based on water current  + sit and wait for prey to come down river  + move towards prey odor Phototaxis: orient based on light cues Anemotaxis: orient based on wind  deer smells predator & runs way from wind carrying odor  insect smells mate and moves towards wind carrying odor Phonotaxis: orient based on sound Aerotaxis: O2 Chemotaxis: chemical concentration gradient Geotaxis: gravity

Magnetotaxis: magnetic field Thermotaxis: temperature Migration: Regular long-distance change in location  via sun, moon, stars visual cues  via magnetic particles in head  via excitation of certain photoreceptors in eye sensitive to long wavelengths emitted by earth’s magnetic field 3. Communication often involves innate behaviors Communication - Transmission, reception and response to signals Signal – stimulus transmitted from one individual to another Several types of signals including:  visual  auditory/ vibratory  odor/ taste  tactile 4. Learned behavior - Modification of behavior based on specific experiences  Imprinting (Lorenz)  Spatial Learning  Associative Learning  Cognition  Habituation o Loss of responsiveness to stimuli that convey little or no new information Imprinting  Irreversible formation of a behavioral response during a “critical (sensitive) period” Spatial Learning  Establishment of a memory that reflects the environment’s spatial structure Associative Learning  Ability to associate one environmental feature with another o Operant conditioning o Classical conditioning Cognition  Awareness, reasoning, recollection, judgment 5. Optimal foraging models balance costs and benefits of particular behaviors

Ch. 52 1. Ecology vs. environmental science vs. environmentalism Ecology  Integration of various biological sciences (anatomy, physiology, genetics, behavior, evolution) mathematics and sometimes other natural sciences (i.e. physics, chemistry, soil science, geology, geography)to study living organisms. Environmental science  Integration of natural sciences (i.e. biology, physics, chemistry, soil science, geology, geography) to understand environmental systems and to help solve environmental problems which may also incorporate the social sciences (i.e. sociology, economics, political science, law), e.g. atmospheric science, environmental chemistry, environmental engineering (water flow, erosion control), climate change, natural resource managment  Conservation biology is a blend of ecology and environmental science focused on protecting and restoring the diversity of life on Earth. Environmentalism (activism)  A social movement that seeks to influence the political process by lobbying, activism, and education in order to protect natural resources  May or may not be based on scientific or other data 2. The science of ecology has diverse approaches Natural History:  Descriptions of organism based on verifiable observations & measurements of distributions, growth, reproduction, survival, feeding, etc. o Can lead to the detection of new patterns or correlations o Which can lead to hypotheses to test Hypothesis Testing:  Explanation of observed patterns and correlations and how they came to be  Can test hypotheses using:  Experiments  Can be in the lab or field and vary in level of complexity e.g. simulated drought conditions o Ecological Models  A representation of an ecological process  Descriptive (verbal, pictorial) e.g. Water cycle diagram o Mathematical e.g. logistic growth model: dn/dt=rN 3. Both Abiotic and Biotic Factors determine organism distribution, abundance and diversity Abiotic  Chemical  Geological  Physical Biotic  Predator/ Prey  Competitors  Mutualism 4. Both Biotic & Abiotic determine organism distribution & abundance

5. Biogeography: Why species are where they are  Abiotic and biotic facotrs  Historical factors o Continental drift o Mass extinctions  Dispersal o Natural range expansions o Species introductions  Behavior 6. 2 brood categories of Biomes  Aquatic - A collection of worldwide regions with similar physical and chemical conditions.  Terrestrial - A collection of worldwide regions with similar climatic conditions.  All of the regions in a biome contain organisms with similar adaptations which allow them to survive the characteristic conditions i.e. convergent evolution Aquatic Biomes  Freshwater o Lakes, Wetlands, Streams & Rivers  Estuaries – link freshwater and marine  Marine o Intertidal o Reef o Pelagic o Benthic Terrestrial Biomes  Tropical Rainforest  Near equator  Broadleaf evergreen trees  Tightly spaced  Many layers 7. Oligotrophic  Nutrient poor  O2 rich Eutrophic  Nutrient rich  O2 poor 8. Turnover in spring brings O2 down and nutrients up Winter – Top layer coldest and progressively warmer with depth Spring – Top layer heats and warmer water sinks, liminating thermal stratification. Equal water densities allow winds to mix water bringing O2 to bottom and nutrients to top Summer – Warm waters at top> H2O gradually cools with depth until thermocline>Thermocline = abrupt temperature drop>Colder lower water gradually cool with additional depth Fall – Top layer cools and sinks, eliminating thermal stratification

9. Wetlands are Classified by location:  Basin – in shallow depressions  Riverine – along periodically flooded river banks  Fringe – around lakes OR by dominant vegetation type:  Marsh – soft emergent vegetation  Swamp – woody emergent vegetation  Bog – moss, peat deposits

10. Temperature and rainfall shape terrestrial biomes

Ch. 53 1. What is Population Ecology? Study of how abiotic and biotic factors influence a species’ distribution, density (or size), age structure & dynamics. Typically do not study the entire species but instead a population  Population - group of individuals of a single species living in the same general area  Distribution - the geographical area within which a species or population occurs. 2. Density - number of individuals per unit area or volume  Can be determined by census or sampling.  Census - Counting ALL individuals in a population (e.g. U.S. Census 3. Estimating population size using Mark-recapture (m/N)=(x/n)→ N=(mn)/x m = # captured and marked in 1st sample x = # recaptured in 2nd sampling n = total # captured in 2nd sampling Example: Period 1: Capture 10 individuals and mark and release them Period 2: Capture 8 individuals of which 4 are already marked N=(mn)/x = (10)(8)/4 = 20 individuals estimated in population 4. Demography – Study of the vital statistics of a population and how they change over time 5. Survivorship - # of individuals from a cohort that survives from birth to age x Different curves show how survivorship probabilities vary among populations. Type I –  High probability of surviving when young  High probability of surviving during middle age  Probability of surviving begins to decrease rapidly as an individual nears the maximum lifespan for the population. Type II –  Equal probability of surviving at all ages from birth to maximum lifespan Type III –  Low probability of surviving when young  Once reach a critical age have a high probability of surviving until near the maximum lifespan of the population.

6. Changes in population size can be modeled mathematically Let: - B = births in population - D = deaths in population - I = immigration into population - E = emigration from population - N = Total population size Thus: N = B – D + I – E Let: - t = time - Δ = change in… Thus the change in population size over a time interval can be represented as: (ΔN/Δt) = B – D + I – E 7. Logistic vs Exponential Growth  Exponential: The larger N, the faster the population grows (i.e. dN/dt increases)  Logistic - At low N, like exponential, population growth rate increases as N increases; BUT as N approaches the maximum population size the environment can support (K), the growth rate slows down; Once N reaches K, the population stops growing (i.e. growth rate (dN/dt = 0) 8. **r is the per capita rate of increase whereas dN/dt is the growth rate of the population** Ch. 54 1. What is Community Ecology? How species interactions affect community composition:  How many species?  Which species?  Relative abundance of species? Community - assemblage of interacting populations of different species 2. Evolutionary outcomes of competitive exclusion principle  Local Extinction  Character Displacement  Resource Partitioning Resource Partitioning - The dividing of scarce resources in order that species with similar requirements can use the resources in different ways, in different places, and at different times. Character Displacement - Characteristics become divergent in sympatric populations compared with Allopatric populations (Sympatric = species live in same location, Allopatric = species live in different places).

Interspecific Interaction

Effect of interaction on survival/reproduction of each individual involved + + + + + + O

Competition Predation Herbivory Parasitism Mutualism Commensalism