Natural Science

Introduction to
B I O L O G I C A L S C I E N C E
A Simplified Approach
05.29.2013

RICHARD M. ADRIANO, RN
0261849
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NATURAL SCIENCE 1
CHAPTER 1
INTRODUCTION TO BIOLOGICAL SCIENCE Biological science is the study of living things. In this context we may ask: What are living things? We humans, ourselves are living things. How do living things differ from non-living things? To answer these questions, we must first define the word life.
Life (cf. biota) is a characteristic that distinguishes objects that have signalling and self-sustaining processes from those that do not, either because such functions have ceased (death), or else because they lack such functions and are classified as inanimate. Biology is the science concerned with the study of life.

Characteristics of Living things vs. Non-living things:

Characteristics | Living | Non-living | 1. Form & Size | With forms and size, arranged as definite individuals | Materials vary widely | 2. Organization | Made up of cells | Structure depends on chemicals present and mode of formation | 3. Movement | Independent | Dependent | 4. Growth & Life Cycle | G- Intussusception (I.G)LC- Definite | G- Accretion (E.G)LC- External addition | 5. Metabolism | Anabolism & Catabolism | None | 6. Irritability | Disproportionate | Definite quantitative | 7. Reproduction | Ability to create | None |

Characteristics of Plants vs. Animals:

Characteristics | Plants | Animals | 1. Form & Structure | Constant body form | Variable body form | 2. Metabolism | Independent | Dependent | 3. Irritability | With Nervous system | Without Nervous system |

A. History of Biology – The Famous Biologist’s and their contributions.

I. Primitive Period
- Uncritical accumulation of information
- No recorded information

II. Classical Period
- Greek and Roman influence
- Curiosity about natural phenomena and ability to organize biological knowledge and record it

1. Hippocrates of Cos or Hippokrates of Kos - He is referred to as the father of medicine in recognition of his lasting contributions to the field as the founder of the Hippocratic School of Medicine.

2. Aristotle
Famous Greek Philosopher
Pioneered Zoology
First to classify living things
Divided the plants into herbs, shrubs and trees and animals into land dwellers, water dwellers and air dwellers

3. Aelius Galenus or Claudius Galenus
Greek physician who describe the anatomy of the human body based on dissections of apes and pigs. showed that arteries carry blood
His description contained many errors, however, and were unchallenged for 1,300 years.

III. Renaissance Period
- Took place during the 14th to 16th centuries

1. Leonardo da Vinci and Michelangelo - made accurate studies in plants, animals and human anatomy.
2. Andreas Vesalius
Father of Modern Anatomy
Made the first studies on human anatomy by dissecting corpses “De Humani Corporis Fabrica”.
He pioneered the comparative approach, which is using other animals to know the function and organization of a particular anatomical part of the body.
3. William Harvey
English physician who showed conclusively that the heart pumps the blood and the blood circulates.
He stimulated the development of anatomy by proving the principle that structure and function must be studied together. Gave an accurate account of the mechanism of the circulatory system
4. Marcello Malpighi
Italian physician and anatomist who was the founder of microscopic anatomy. In 1661, he discovered the capillaries, shedding light to the missing element in Harvey’s theory of blood circulation. Observed the microscopic components of the liver, brain, kidneys, spleen, bone, and the inner, or what came to be known as the Malpighian, layer of the skin discover red blood corpuscles
5. Anton van Leeuwenhoek
Cloth merchant, was the first to use the microscope with great observational and descriptive skills.
His most important discoveries were microorganisms (including bacteria), sperm cells and single-celled organisms called protozoans.

IV. Modern Period
- Took place during the 17th to 20th centuries

1. Robert Hooke - “Cell Theory”
2. Matthias Schleiden (botanist) & Theodore Schwann (zoologist) - spontaneous origin of life from non-living matter
3. Francesco Redi - refuted "spontaneous generation" - a theory also known as Aristotelian abiogenesis. At the time, prevailing wisdom was that maggots formed naturally from rotting meat.
4. Carolus Linnaeus “Father of Taxonomy”
Developed binomial nomenclature to classify and organize plants and animals
5. Jean Baptiste Lamarck - proposed theory of evolution
6. Charles Darwin
The most prominent figure in the history of biology.
His book “Origin of Species” (1859) presents the theory of evolution by natural selection.
His work provided a unifying, organizing framework for the field of biology.
7. Louis Pasteur -“Father of Modern Microbiology”
8. Gregor Mendel
Father of Genetics
Developed the principles of heredity by studying the variation and heredity of seven pairs of inherited characteristics in pea plants.
9. Leon Ma. Guerrero
Father of Philippine Pharmacophytology.
He identified hundreds of trees and herbs and sought to extract from them certain substances with therapeutic properties. First to identify and describe plants that poison fish.
10. Angel S. Arguelles
Taught Filipino planters and farmers how to use fertilizers and pesticides. His name is listed among the “American Men of Science” (He is not an American)
11. Nemesio L. Mendiola
Introduced better varieties of fruits, vegetables and flowering plants.
Breed a new variety of pineapple that has the sweetness of the Hawaiian pineapple and the high yield of the native pineapple.
He was referred to as the “Luther Burbank” of the Philippines.
12. Felix D. Maramba Sr.
Popular in the fields of agriculture and business.
He contributed a machine that could turn rice hull into fuels for farm engines, a charcoal and a coconut-oil fed power generator and the biogas technology.
Other researches of Maramba are production of alcohol from cassava, soap from lye, and pelletized sludge organic fertilizer.
He was indeed a man of ingenuity in agricultural technology.
13. Juan Salcedo
Launched the biggest project in the history of Philippine medicine – the inclusion of enriched rice in the Filipino diet.
*Enriched rice is fortified with vitamin B1 to cure beri-beri.
He took other projects like the extensive drive to combat mosquitoes which carry malaria germs, and the use of the vaccine BCG to combat tuberculosis.
He was among the first batch of national scientists named by the National Academy of Science and Technology (NAST).
14. Fe Del Mundo
Invented the incubator and the jaundice-relieving device for babies.
She conducted an experiment on immunization that help designate the best age at which children should be immunized.
She wrote many books and research papers on pediatrics.
She was proclaimed a National Scientist in 1980.

B. Branches of Biology

Botany is the study of plants.
Zoology is the study of animals.
Anatomy is the study of internal structures of living things.
Biochemistry is the use of chemistry in the study of living things.
Biological Earth Science is the use of earth sciences, such as geography in the study of living things.
Biological Psychology is the use of biology in psychological studies.
Biomathematics is the use of mathematics in the study of living things.
Biophysics is the use of physics in the study of living things.
Ecology is the study of the relationships of living things to each other and to their environment.
Pathology is the study if diseases, generally in animals. Phytopathology is the study of diseases in plants.
Physiology is the study of normal functions of living things.
Taxonomy is the classification and naming of living things.
Genetics is the science of heredity and the lifelong development of living things
Embryology is the study of the formation and development of living things from fertilization to birth as independent organisms.
Pharmacology is the study of the actions of chemicals on and in living things.
Endocrinology is the study of hormones and their actions.
Cytology is the study of cells.
Histology is the study of tissues.
Protozoology is the study of one celled organisms.
Bacteriology is the study of bacteria.
Virology is the study of viruses.
Mammalogy is the study of mammals.
Ornithology is the study of birds.
Herpetology is the study of reptiles and amphibians,
Ichthyology is the study of fishes.
Entomology is the study of insects.
Helminthology is the study of worms.
Microbiology is the study of microorganisms.
Mycology is the study of fungi.
Phycology is the study of algae.
Liehenology is the study of lichens.
Paleontology is the study of fossils.
Biogeography is the study of geographical distribution of living things.
Phytogeography is the study of the land and its plants.
Zoogeography is the study of the land and its animals.

CHAPTER 2 BASIC CHEMISTRY

Matter is defined as anything that has mass and volume.
Mass is a measure of an object's inertia. It is proportional to weight: the more mass an object has, the more weight it has.
Volume is a measure of the amount of space occupied by an object.
Amount of substance, This can either represent a counted quantity of objects (e.g. three mice or a dozen bagels) or the indirectly determined number of particles of a substance being dealt with such as how many atoms are contained in a sample of a pure substance.
Atom: A fundamental building block of matter composed of protons, neutrons, and electrons.
Element: A uniquely identifiable atom recognized by the number of protons in the nucleus.

Nucleus
The nucleus is the center of the atom, around which, the electrons orbit. It contains neutrons, which have no electrical charge, and protons, which carry a positive charge.

Protons
A proton has a positive electrical charge, which, for reasons which will become clear in the electrons section, makes them attracted to electrons. These protons are located in the nucleus and are about the same weight as neutrons, which are also located within the nucleus. How Protons Were

Electrons
Electrons are locate within the electron cloud. In terms of mass, the electron cloud has less than that of the nucleus. In terms of volume, however, it takes up the most. Electrons are negatively charged, which makes them electrically attracted to protons. This attraction enables electrons to orbit around the nucleus of the atom.

Isotope – Consisting of the same amount of protons but different number of neutrons within a nucleus, isotopes are two forms of the same element. Examples include Carbon-12 and Carbon 14.

Ion – An atom that has a positive or negative charge because of the loss or acquisition of an electron.

Ionic Bond – The kind of bond which is the result of one atom being removed and attached to another. The result of this action is the existence of positive and negative bonds being attracted to one another.

Atomic Mass Unit – The term used for measuring the weight of an atom. AMU is also called a Dalton (Da).

Molecule – Formed when two or more atoms combine chemically, molecules differ from compounds because they are formed when two of the same atoms join together. Examples include hydrogen (H2), oxygen (O2), and nitrogen (N2).

Periodic Table of Elements – A way of arranging the elements in an effort to predict their properties based on their location on the table.

Dmitri Mendeleev is generally credited with the publication, in 1869, of the first widely recognized periodic table. He developed his table to illustrate periodic trends in the properties of the then-known elements. Mendeleev also predicted some properties of then-unknown elements that would be expected to fill gaps in this table. Most of his predictions were proved correct when the elements in question were subsequently discovered. Mendeleev's periodic table has since been expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behavior.

List of chemical elements ordered by increasing atomic number. The names and element symbols are provided.

1 - H - Hydrogen2 - He - Helium3 - Li - Lithium4 - Be - Beryllium5 - B - Boron6 - C - Carbon7 - N - Nitrogen8 - O - Oxygen9 - F - Fluorine10 - Ne - Neon11 - Na - Sodium12 - Mg - Magnesium13 - Al - Aluminum, Aluminium14 - Si - Silicon15 - P - Phosphorus16 - S - Sulfur17 - Cl - Chlorine18 - Ar - Argon19 - K - Potassium20 - Ca - Calcium21 - Sc - Scandium22 - Ti - Titanium23 - V - Vanadium24 - Cr - Chromium25 - Mn - Manganese26 - Fe - Iron27 - Co - Cobalt28 - Ni - Nickel29 - Cu - Copper30 - Zn - Zinc31 - Ga - Gallium32 - Ge - Germanium33 - As - Arsenic34 - Se - Selenium35 - Br - Bromine36 - Kr - Krypton37 - Rb - Rubidium38 - Sr - Strontium39 - Y - Yttrium40 - Zr - Zirconium41 - Nb - Niobium42 - Mo - Molybdenum43 - Tc - Technetium44 - Ru - Ruthenium45 - Rh - Rhodium46 - Pd - Palladium47 - Ag - Silver48 - Cd - Cadmium49 - In - Indium50 - Sn - Tin51 - Sb - Antimony52 - Te - Tellurium53 - I - Iodine54 - Xe - Xenon55 - Cs - Cesium56 - Ba - Barium57 - La - Lanthanum58 - Ce - Cerium59 - Pr - Praseodymium | 60 - Nd - Neodymium61 - Pm - Promethium62 - Sm - Samarium63 - Eu - Europium64 - Gd - Gadolinium65 - Tb - Terbium66 - Dy - Dysprosium67 - Ho - Holmium68 - Er - Erbium69 - Tm - Thulium70 - Yb - Ytterbium71 - Lu - Lutetium72 - Hf - Hafnium73 - Ta - Tantalum74 - W - Tungsten75 - Re - Rhenium76 - Os - Osmium77 - Ir - Iridium78 - Pt - Platinum79 - Au - Gold80 - Hg - Mercury81 - Tl - Thallium82 - Pb - Lead83 - Bi - Bismuth84 - Po - Polonium85 - At - Astatine86 - Rn - Radon87 - Fr - Francium88 - Ra - Radium89 - Ac - Actinium90 - Th - Thorium91 - Pa - Protactinium92 - U - Uranium93 - Np - Neptunium94 - Pu - Plutonium95 - Am - Americium96 - Cm - Curium97 - Bk - Berkelium98 - Cf - Californium99 - Es - Einsteinium100 - Fm - Fermium101 - Md - Mendelevium102 - No - Nobelium103 - Lr - Lawrencium104 - Rf - Rutherfordium105 - Db - Dubnium106 - Sg - Seaborgium107 - Bh - Bohrium108 - Hs - Hassium109 - Mt - Meitnerium110 - Ds - Darmstadtium111 - Rg - Roentgenium112 - Cn - Copernicium113 - Uut - Ununtrium114 - Fl - Flerovium115 - Uup - Ununpentium116 - Lv - Livermorium117 - Uus - Ununseptium118 - Uuo - Ununoctium |

Properties of Matter * Properties of matter can be divided in two ways: extensive/intensive, or physical/chemical.

1. Extensive properties depend on the amount of matter that is being measured. These include mass and volume.
2. Intensive properties do not depend on the amount of matter. These include density and color.
3. Physical properties can be measured without changing the chemical's identity. The freezing point of a substance is physical. When water freezes, it's still H2O.
4. Chemical properties deal with how one chemical reacts with another. We know that wood is flammable because it becomes heat, ash, and carbon dioxide when heated in the presence of oxygen.

State of Matter

1. Solids
Solids have a definite shape and a definite volume. Most everyday objects are solids: rocks, chairs, ice, and anything with a specific shape and size. The molecules in a solid are close together and connected by intermolecular bonds.
2. Liquids
Liquids have a definite volume, but they do not have a definite shape. Instead, they take the shape of their container to the extent they are indeed "contained" by something such as beaker or a cupped hand or even a puddle.
3. Gases
Gases have no definite volume and no definite shape. They expand to fill the size and shape of their container. The oxygen that we breathe and steam from a pot are both examples of gases. The molecules are very far apart in a gas, and there are minimal intermolecular forces.

Kinds of Matter

1. Element – a substance which is defined by how many protons it possesses and cannot be broken down into smaller parts through the use of chemical means.
2. Compounds – Formed when two or more elements join together through ionic or covalent bonds, examples of compounds are water (H2O), carbon dioxide (CO2), and methane (CH4).
3. Mixture – made up of two or more pure substances jumbled together either homogeneously or heterogeneously.

Important Inorganic Compounds

There are 6 basic nutrients that the body needs in order to provide energy, repair and support tissue growth and to regulate metabolism. These nutrients are needed for maintaining optimal health and performance.

1. Carbohydrates are your primary energy source for the body. They’re also fuel for your muscles and brain.
2. Protein is essential for building and repairing muscles, red blood cells, hair and other tissues. It’s also needed for the manufacture of hormone enzymes and antibody function.
3. Fats are needed as a cushion for your vital organs. They are also needed to transport and dissolve fat soluble vitamins.
3. Water helps improve liver functioning and prevents dehydration. Water also acts as an appetite suppressant by making you feel more full. The thermo regulation of your body is completely dependent upon water.
4. Vitamins perform a variety of functions including their assistance with building body tissues, their action in the metabolism of proteins, fats and carbohydrates, and their role in the prevention of nutritional deficiency diseases as well as the promotion of good health.
5. Minerals are found in plants and animal foods and play a very significant role in various bodily functions essential to physical movement. A deficiency in any mineral can alter your performance on the golf course. The total amounts of minerals in the body are relatively small, but each is crucial to cell function. The major minerals of interest are Calcium and Iron.

Basic Food Groups

Basic Vitamins

Basic Minerals

CHAPTER 3 THE CELL

The cell is the basic structural, functional and biological unit of all known living organisms. It is the smallest unit of life that is classified as a living thing (except virus, which consists only of DNA/RNA covered by protein and lipids), and is often called the building block of life.

It consists of a protoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Organisms can be classified as unicellular (consisting of a single cell; including most bacteria) or multicellular (including plants and animals).

There are two types of cells: Eukaryote and prokaryote. Prokaryotic cells are usually independent, while eukaryotic cells can either exist as a single celled organism or be found in multicellular organisms.

Table 1: Comparison of features of prokaryotic and eukaryotic cells | | Prokaryotes | Eukaryotes | Typical organisms | bacteria, archaea | protists, fungi, plants, animals | Typical size | ~ 1–5 µm[7] | ~ 10–100 µm[7] (sperm cells, apart from the tail, are smaller) | Type of nucleus | nucleoid region; no real nucleus | real nucleus with double membrane | DNA | circular (usually) | linear molecules (chromosomes) with histone proteins | RNA-/protein-synthesis | coupled in cytoplasm | RNA-synthesis inside the nucleus protein synthesis in cytoplasm | Ribosomes | 50S+30S | 60S+40S | Cytoplasmatic structure | very few structures | highly structured by endomembranes and a cytoskeleton | Cell movement | flagella made of flagellin | flagella and cilia containing microtubules; lamellipodia and filopodia containing actin | Mitochondra | none | one to several thousand (though some lack mitochondria) | Chloroplasts | none | in algae and plants | Organization | usually single cells | single cells, colonies, higher multicellular organisms with specialized cells | Cell division | Binary fission (simple division) | Mitosis (fission or budding)
Meiosis |

Structure of a typical animal cell

Structure of a typical plant cell

Table 2: Comparison of structures between animal and plant cells | | Typical animal cell | Typical plant cell | Organelles | * Nucleus * Nucleolus (within nucleus) * Rough endoplasmic reticulum (ER) * Smooth ER * Ribosomes * Cytoskeleton * Golgi apparatus * Cytoplasm * Mitochondria * Vesicles * Lysosomes * Centrosome * Centrioles | * Nucleus * Nucleolus (within nucleus) * Rough ER * Smooth ER * Ribosomes * Cytoskeleton * Golgi apparatus (dictiosomes) * Cytoplasm * Mitochondria * Plastids and its derivatives * Vacuole(s) * Cell wall |

A. Cell Parts and Their Functions

1. Nucleus
- Large Oval body near the centre of the cell.
- The control centre for all activity.
- Surrounded by a nuclear membrane.
2. Nucleoplasm
- is the protoplasm in the nucleus.
- contains genetic material ---> CHROMOSOMES (DNA)
3. Nucleolus
- is found in the nucleus.
- contains more genetic information (RNA)
4. Cell Membrane
- the outer boundary of the cell.
- it separates the cell from other cells.
- it is porous ---> allows molecules to pass through.
5. Cell Wall ( Plant Cells Only )
- non living structure that surrounds the plant cell.
- protects + supports the cell.
- made up of a tough fibre called cellulose.
6. Cytoplasm
- cell material outside the nucleus but within the cell membrane.
- clear thick fluid.
- contains structures called organelles.
7. Vacuoles
- are clear fluid sacs that act as storage areas for food, minerals, and waste.
- in plant cell the vacuoles are large and mostly filled with water. This gives the plant support.
- in animal cells the vacuoles are much smaller.
8. Mitochondria
- power house of the cell.
- centre of respiration of the cell.
- they release energy for cell functions.
9. Chloroplasts ( Plant cells only )
- contains a green pigment known as chlorophyll which is important for photosynthesis.
10. Ribosomes
- tiny spherical bodies that help make proteins.
- found in the cyto plasm or attached to the endo plasmic reticulum.
11. Endoplasmic Reticulum ( ER )
- systems of membranes throughout the cyto plasm.
- it connects the nuclear membrane to the cell membrane.
- passageway for material moving though the cell.
12. Golgi Bodies
- tube like structures that have tiny sacs at their ends.
- they help package protein.
13. Lysosomes
- " suicide sacs "
- small structures that contain enzymes which are used in digestion.
- if a lysosome were to burst it could destroy the cell.

THE TISSUE

In Biology, tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.

1 Animal tissues
1.1 Connective tissue
1.2 Muscle tissue
1.3 Nervous tissue
1.4 Epithelial tissue

2 Plant tissues
2.1 Meristematic tissues
2.2 Permanent tissues
2.2.1 Simple permanent tissues
2.2.1.1 Parenchyma
2.2.1.2 Collenchyma
2.2.1.3 Sclerenchyma
2.2.1.4 Epidermis
2.2.2 Complex permanent tissue
2.2.2.1 Xylem
2.2.2.2 Phloem

1.1 Connective tissue
Connective tissues are fibrous tissues. They are made up of cells separated by non-living material, which is called extracellular matrix. Connective tissue gives shape to organs and holds them in place. Both blood and bone are examples of connective tissue. As the name implies, these support and bind other tissues. Unlike epithelial tissue, connective tissue typically has cells scattered throughout an extracellular matrix.
1A. Supporting connective tissue
Gives strength, support, and protection to the soft parts of the body. * cartilage. Example: the outer ear * bone. The matrix of bone contains collagen fibers and mineral deposits. The most abundant mineral is calcium phosphate, although magnesium, carbonate, and fluoride ions are also present. [More on bone]
1B. Dense connective tissue
Often called fibrous connective tissue. * Tendons connect muscle to bone.The matrix is principally Type I collagen, and the fibers are all oriented parallel to each other. Tendons are strong but not elastic. * Ligaments attach one bone to another. They contain both collagen and also the protein elastin. Elastin permits ligaments to be stretched.
1C. Loose connective tissue
It is distributed throughout the body. It serves as a packing and binding material for most of our organs. Sheets of loose connective tissue that bind muscles and other structures together are called fascia. Collagen, elastin, and other proteins are found in the matrix of loose connective tissue.
1.2 Muscle Tissue
Muscle cells form the active contractile tissue of the body known as muscle tissue or muscular tissue. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs.
Three kinds of muscle are found in vertebrates: * Skeletal muscle is made of long fibers whose contraction provides the force of locomotion and other voluntary body movements. * Smooth muscle lines the walls of the hollow structures of the body, such as the intestine, urinary bladder, uterus, and blood vessels. Its contraction, which is involuntary, reduces the size of these hollow organs. * The heart is made of cardiac muscle.
1.3 Nervous Tissue
Cells comprising the central nervous system and peripheral nervous system are classified as neural tissue.

In the central nervous system, neural tissue forms: - the brain and
- spinal cord and,
In the peripheral nervous system forms:
- the cranial nerves and
- spinal nerves, inclusive of the motor neurons.

Nervous tissue functions to transmit messages in form of impulse.
Neurons

Neurons are specialized for the conduction of nerve impulses. A typical neuron consists of * a cell body which contains the nucleus; * a number of short fibers — dendrites — extending from the cell body * a single long fiber, the axon.
The nerve impulse is conducted along the axon.
1.4 Epithelial Tissue

The epithelial tissues are formed by cells that cover the organ surfaces such as the surface of the skin, the airways, the reproductive tract, and the inner lining of the digestive tract. The cells comprising an epithelial layer are linked via semi-permeable, tight junctions; hence, this tissue provides a barrier between the external environment and the organ it covers. In addition to this protective function, epithelial tissue may also be specialized to function in secretion and absorption. Epithelial tissue helps to protect organisms from microorganisms, injury, and fluid loss. Functions: * the cell of the body surface form the outer layer of skin. * inside the body,epithelial cells forms lining of mouth & alimentary canal & protect these organ. * epithelial tissues help in absorption of water & nutrient. * epithelial tissues help in elimination of waste product.
The different types of epithelial tissues are as follows: * Squamous epithelium, * Cuboidal epithelium, * Columnar epithelium, * Glandular epithelium, * Ciliated epithelium.

CHAPTER 4 THE ORGAN SYSTEM
THE ORGAN
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function.

There is a "main" tissue, parenchyma, and "sporadic" tissues, stroma. The main tissue is the one that is unique for the specific organ. For example, the main tissue in the heart is the myocardium, while sporadic tissues include the nerves, blood and connective tissues. Functionally related organs often cooperate to form whole organ systems. Organs exist in all higher biological organisms, in particular they are not restricted to animals, but can also be identified in plants. In single-cell organisms like bacteria, the functional analogues of organs are called organelles.
A hollow organ is a visceral organ that is a hollow tube or pouch, such as the stomach or intestine, or that includes a cavity, like the heart or urinary bladder.

The 11 Systems in the Human Body
1. Circulatory system: pumping and channelling blood to and from the body and lungs with heart, blood and blood vessels.
2. Integumentary system: skin, hair, fat, and nails.
3. Skeletal system: structural support and protection with bones, cartilage, ligaments lia and nana and tendons.
4. Reproductive system: the sex organs, such as ovaries, fallopian tubes, uterus, vagina, mammary glands, testes, vas deferens,seminal vesicles and prostate
5. Digestive system: digestion and processing food with salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines,rectum and anus.
6. Urinary system: kidneys, ureters, bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.
7. Respiratory system: the organs used for breathing, the pharynx, larynx, bronchi, lungs and diaphragm.
8. Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitarygland, pineal body or pineal gland, thyroid, parathyroids and adrenals, i.e., adrenal glands.
9. Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream; includes the lymph and thenodes and vessels.
10. Muscular system: allows for manipulation of the environment, provides locomotion, maintains posture, and produces heat. Includes only skeletal muscle, not smooth muscle or cardiac muscle.
11. Nervous system: collecting, transferring and processing information with brain, spinal cord and peripheral nervous system.

These specific systems are widely studied in Human anatomy. "Human" systems are also present in many other animals.

Circulatory System

Integumentary System

Skeletal System

Reproductive System

Digestive System

Urinary System

Respiratory System

Endocrine System

Lymphatic System

Muscular System

Nervous System

CHAPTER 5
THE EVOLUTION

HISTORY OF EARLY EARTH & ITS GEOLOGICAL TIMETABLE

Approximately 3,000 million years ago, the earth was cool enough for land masses to form. The supercontinent Rodinia was formed about 1100 million years ago, and it broke into several pieces that drifted apart 750 million years ago. Those pieces came back together about 600 million years ago, forming the Pan-African mountains in a new supercontinent called Pannotia. Pannotia started breaking up 550 million years ago to form Laurasia and Gondwana. Laurasia included what are now North America, Europe, Siberia, and Greenland. Gondwana included what is now India, Africa, South America, and Antarctica. Laurasia and Gondwana rejoined approximately 275 million years ago to form the supercontinent of Pangea. The break up of Pangea, which still goes on today, has contributed to the formation of the Atlantic Ocean.
The basic timeline of a 4.6 billion year old Earth, with approximate dates: * 3.6 billion years of simple cells (prokaryotes), * 3.4 billion years of stromatolites demonstrating photosynthesis, * 2 billion years of complex cells (eukaryotes), * 1 billion years of multicellular life, * 600 million years of simple animals, * 570 million years of arthropods (ancestors of insects, arachnids and crustaceans), * 550 million years of complex animals, * 500 million years of fish and proto-amphibians, * 475 million years of land plants, * 400 million years of insects and seeds, * 360 million years of amphibians, * 300 million years of reptiles, * 200 million years of mammals, * 150 million years of birds, * 130 million years of flowers, * 66 million years since the dinosaurs died out, * 20 million years since the appearance of the family Hominidae (great apes) * 2.5 million years since the appearance of the genus Homo (human predecessors) * 200,000 years since the appearance of anatomically modern humans, * 25,000 years since the disappearance of Neanderthal traits from the fossil record. * 13,000 years since the disappearance of Homo floresiensis from the fossil record.

Eon: Half a billion years or more.
Era: Several hundred million years.
Epoch: Tens of millions of years.
Age: Millions of years.

Development of Life During The Eras

Paleozoic Era Period | MYA | Life Forms | Cambrian | 600-500 | Algae and simple invertebrates, like jellyfish & worms. Arthropods, brachiopods, & trilobites. | Ordovician | 500-440 | Graptolites, orthocerous, & primitive fish. The first vertebrates begin to appear. | Silurian | 440-395 | The first true plants appear. Crinoids & eurypterids are abundant. The first air breathers. | Devonian | 395-345 | Fish evolve into more complex animals. Sharks and amphibians multiply. | Carboniferous | 345-280 | Plentiful ferns. Reptiles evolve. Spiders, cockroaches, & scorpions appear. Life on dry land. | Permian | 280-225 | Reptiles become abundant. Pine-like trees develop. Trilobites become extinct. |

Mesozoic Era Period | MYA | Life Forms | Triassic | 225-190 | The beginning of the dinosaurs. Plant eaters, meat eaters, flying reptiles, and crocodiles. | Jurassic | 190-136 | Giant dinosaurs develop. Abundant plant life & shellfish, like ammonites, lobsters, and shrimp. | Cretaceous | 136-65 | The peak of development. Downfall of the great dinosaurs, like triceratops, t-rex, & pterodactyls. Deciduous trees develop. |

Cenozoic Era Period | MYA | Life Forms | Tertiary | 65-2 | Mammals develop, such as camels, bears, cats, monkeys, rodents, and dogs. Grasses & fruit like todays appear. | Quaternary | 2-Present | More mammals develop, like the saber-toothed tiger and mastodon. Modern man appears. | EARLY LIFE CHART

EVOLUTION
Evolution is the change in the inherited characteristics of biological populations over successive generations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.

1. Jean-Baptiste Lamarck
Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck, was a French naturalist. He was a soldier, biologist, academic, and an early proponent of the idea that evolution occurred and proceeded in accordance with natural laws. He gave the term biology a broader meaning by coining the term for special sciences, chemistry, meteorology, geology, and botany-zoology.

Lamarck’s Theory of Evolution
1. Theory of Need
2. Theory of Use and Disuse
3. Theory of Inheritance of Acquired Character

2. Charles Robert Darwin
Charles Robert Darwin, FRS (12 February 1809 – 19 April 1882) was an English naturalist.[I] He established that all species of life have descended over time from common ancestors,[1] and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.

Theory of Natural Selection
1. Overproduction
2. Struggle for Existence
3. Variation among Individuals
4. Transmission of the variations to the Offsprings

3. Hugo de Vries
Hugo Marie de Vries (Dutch pronunciation: [ˈhyxoː də ˈvriːs]) (February 16, 1848, Haarlem – May 21, 1935, Lunteren) was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes, rediscovering the laws of heredity in the 1890s while unaware of Gregor Mendel's work, for introducing the term "mutation", and for developing a mutation theory of evolution.

Mutation Theory
In his own time, De Vries was best known for his mutation theory. In 1886 he had discovered new forms among a display of the evening primrose (Oenothera lamarckiana) growing wild in a meadow. Taking seeds from these, he found that they produced many new varieties in his experimental gardens; he introduced the term mutations for these suddenly appearing variations.

4. Gregor Mendel
Gregor Johann Mendel (July 20, 1822– January 6, 1884) was a German-speaking Silesian scientist and Augustinian friar who gained posthumous fame as the founder of the new science of genetics. Mendel demonstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance.

Mendelian inheritance
Between 1856 and 1863, he cultivated and tested some 29,000 pea plants. From these experiments, he deduced two generalizations which later became known as Mendel's Principles of Heredity or Mendelian inheritance.

1. Law of Segregation (The "First Law")
The Law of Segregation states that every individual possesses a pair of alleles (assuming diploidy) for any particular trait and that each parent passes a randomly selected copy (allele) of only one of these to its offspring. The offspring then receives its own pair of alleles for that trait. Whichever of the two alleles in the offspring is dominant determines how the offspring expresses that trait (e.g. the color and height of a plant, or the color of an animal's fur).

2. Law of Independent Assortment (The "Second Law")
The Law of Independent Assortment, also known as "Inheritance Law", states that separate genes for separate traits are passed independently of one another from parents to offspring. That is, the biological selection of a particular gene in the gene pair for one trait to be passed to the offspring has nothing to do with the selection of the gene for any other trait.

Species and Speciation

Species a species (plural: species) is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.

Speciation
Speciation is the evolutionary process by which new biological species arise.

Natural Speciation Mechanisms

1. Speciation Rate

The rate at which speciation events occur over geologic time.

2. Allopatric

A population splits into two geographically isolated populations (for example, by habitat fragmentation due to geographical change such as mountain building).

3. Peripatric

A subform of allopatric speciation, new species are formed in isolated, smaller peripheral populations that are prevented from exchanging genes with the main population.

4. Parapatric

There is only partial separation of the zones of two diverging populations afforded by geography; individuals of each species may come in contact or cross habitats from time to time.

5. Sympatric

Refers to the formation of two or more descendant species from a single ancestral species all occupying the same geographic location.

CHAPTER 6 ECOLOGY

Ecology is the scientific study of the relationships that living organisms have with each other and with their abiotic environment.

Ecologists seek to explain:
1. Life processes, interactions and adaptations
2. The movement of materials and energy through living communities
3. The successional development of ecosystems, and
4. The abundance and distribution of organisms and biodiversity in the context of the environment.

Ecological Terms

1. Ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the non-living components of their environment (things like air, water and mineral soil), interacting as a system.

2. Biodiversity (an abbreviation of "biological diversity") describes the diversity of life from genes to ecosystems and spans every level of biological organization.

3. Habitat of a species describes the environment over which a species is known to occur and the type of community that is formed as a result.

4.Niche is the set of biotic and abiotic conditions in which a species is able to persist and maintain stable population sizes.

5. Biomes are larger units of organization that categorize regions of the Earth's ecosystems, mainly according to the structure and composition of vegetation.

6. Biosphere is the total sum of ecosystems on the planet.

7. Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals.

Different Environmental Cycles

1. Water and Water Cycle
Water is a chemical compound with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at standard ambient temperature and pressure, but it often co-exists on Earth with its solid state, ice, and gaseous state (water vapor or steam).

-Water covers 71% of the Earth's surface, and is vital for all known forms of life.
-On Earth, 96.5% of the planet's water is found in oceans,
-1.7% in groundwater,
-1.7% in glaciers and the ice caps of Antarctica and Greenland, a small fraction in other large water bodies, and
-0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation.
-Only 2.5% of the Earth's water is freshwater,
-and 98.8% of that water is in ice and groundwater. -Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere,
-and an even smaller amount of the Earth's freshwater (0.003%) is contained within biological bodies and manufactured products.

Processes
1. Precipitation
Condensed water vapor that falls to the Earth's surface . Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet. Approximately 505,000 km3 (121,000 cu mi) of water falls as precipitation each year, 398,000 km3 (95,000 cu mi) of it over the oceans. The rain on land contains 107,000 km3 (26,000 cu mi) of water per year and a snowing only 1,000 km3 (240 cu mi).
2. Canopy interception
The precipitation that is intercepted by plant foliage, eventually evaporates back to the atmosphere rather than falling to the ground.
3. Snowmelt
The runoff produced by melting snow.
4. Runoff
The variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may seep into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.
5. Infiltration
The flow of water from the ground surface into the ground. Once infiltrated, the water becomes soil moisture or groundwater.
6. Subsurface flow
The flow of water underground, in the vadose zone and aquifers. Subsurface water may return to the surface (e.g. as a spring or by being pumped) or eventually seep into the oceans. Water returns to the land surface at lower elevation than where it infiltrated, under the force of gravity or gravity induced pressures. Groundwater tends to move slowly, and is replenished slowly, so it can remain in aquifers for thousands of years.
7. Evaporation
The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. The source of energy for evaporation is primarily solar radiation. Evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. Total annual evapotranspiration amounts to approximately 505,000 km3 (121,000 cu mi) of water, 434,000 km3 (104,000 cu mi) of which evaporates from the oceans.
8. Sublimation
The state change directly from solid water (snow or ice) to water vapor.
9. Deposition
This refers to changing of water vapor directly to ice.
10. Advection
The movement of water — in solid, liquid, or vapor states — through the atmosphere. Without advection, water that evaporated over the oceans could not precipitate over land.
11. Condensation
The transformation of water vapor to liquid water droplets in the air, creating clouds and fog.
12. Transpiration
The release of water vapor from plants and soil into the air. Water vapor is a gas that cannot be seen.
13. Percolation
Water flows horizontally through the soil and rocks under the influence of gravity

2. Carbon and Carbon Cycle
Carbon (from Latin: carbo "coal") is the chemical element with symbol C and atomic number 6.

The global carbon cycle is now usually divided into the following major reservoirs of carbon interconnected by pathways of exchange:
1. The atmosphere
2. The terrestrial biosphere
3. The oceans, including dissolved inorganic carbon and living and non-living marine biota
4. The sediments, including fossil fuels, fresh water systems and non-living organic material, such as soil carbon
5. The Earth's interior, carbon from the Earth's mantle and crust. These carbon stores interact with the other components through geological processes

3. Nitrogen and Nitrogen Cycle
Nitrogen is a chemical element with symbol N and atomic number 7. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.09% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.

Ecosystem Concepts
The three basic ways in which organisms get food are as producers, consumers and decomposers.
1. Producers (autotrophs) are typically plants or algae. Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers. In this way, it is energy from the sun that usually powers the base of the food chain. An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight. Here primary producers manufacture food through a process called chemosynthesis.[2]
2. Consumers (heterotrophs) are animals which cannot manufacture their own food and need to consume other organisms. Animals that eat primary producers (like plants) are called herbivores. Animals that eat other animals are called carnivores, and animals that eat both plant and other animals are called omnivores.
3. Decomposers (detritivores) break down dead plant and animal material and wastes and release it again as energy and nutrients into the ecosystem for recycling. Decomposers, such as bacteria and fungi (mushrooms), feed on waste and dead matter, converting it into inorganic chemicals that can be recycled as mineral nutrients for plants to use again.
Trophic levels can be represented by numbers, starting at level 1 with plants. Further trophic levels are numbered subsequently according to how far the organism is along the food chain.
Level 1: Plants and algae make their own food and are called primary producers.
Level 2: Herbivores eat plants and are called primary consumers.
Level 3: Carnivores which eat herbivores are called secondary consumers.
Level 4: Carnivores which eat other carnivores are called tertiary consumers.
Level 5: Apex predators which have no predators are at the top of the food chain.

Second trophic level
Rabbits eat plants at the first trophic level, so they are primary consumers.

Third trophic level
Foxes eat rabbits at the second trophic level, so they are secondary consumers.

Fourth trophic level
Golden eagles eat foxes at the third trophic level, so they are tertiary consumers.

Decomposers
The fungi on this tree feed on dead matter, converting it back to nutrients that primary producers can use.

ECOLOGICAL PYRAMID
An ecological pyramid (also trophic pyramid or energy pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.
Biomass is the amount of living or organic matter present in an organism. Biomass pyramids show how much biomass is present in the organisms at each trophic level, while productivity pyramids show the production or turnover in biomass.
Ecological pyramids begin with producers on the bottom (such as plants) and proceed through the various trophic levels (such as herbivores that eat plants, then carnivores that eat herbivores, then carnivores that eat those carnivores, and so on). The highest level is the top of the food chain.

FOOD CHAIN
A food chain is a linear sequence of links in a food web starting from a species that eats no other species in the web and ends at a species that is eaten by no other species in the web.

FOOD WEB
A food web (or food cycle) depicts feeding connections (what-eats-what) in an ecological community and hence is also referred to as a consumer-resource system.

CHAPTER 7
CLASSIFICATION AND NOMENCLATURE

TAXONOMY
Taxonomy is a hierarchical system for classifying and identifying organisms.
-is the academic discipline of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. Each group is given a rank and groups of a given rank can be aggregated to form a super group of higher rank and thus create a hierarchical classification. The groups created through this process are referred to as taxa (singular taxon).

Carolus Linnaeus (1707-1778) was a Swedish biologist. He is considered as a pioneer in the field of taxonomy and referred to as “Father of Taxonomy”.

Binomial Nomenclature

Linnaeus's taxonomy system has two main features that contribute to its ease of use in naming and grouping organisms. The first is the use of binomial nomenclature. This means that an organism's scientific name is comprised of a combination of two terms. These terms are the genus name and the species or epithet. Both of these terms are italicized and the genus name is also capitalized.

Example

Humans = Homo sapiens

Philippine Monkey-eating Eagle = Pithecophaga jefferyi

Classification Categories

The second feature of Linnaeus's taxonomy system that simplifies organism classification is the ordering of species into broad categories. There are seven major categories: Kingdom, Phylum, Class, Order, Family, Genus, and Species.

A good aid for remembering these categories is the mnemonic device: Keep Plates Clean Or Family Gets Sick.

Some of these categories can be further divided into intermediate categories such as subphyla, suborders, superfamilies, and superclasses. An example of this taxonomy scheme is:

Kingdom
Phylum
Subphylum
Superclass
Class
Subclass
Superorder
Order
Suborder
Superfamily
Family
Subfamily
Genus
Subgenus
Species
Subspecies

Taxonomy of Organisms Classification | | | Brown Bear | House Cat | Dog | Killer Whale | Wolf | | K | Animalia | Animalia | Animalia | Animalia | Animalia | | P | Chordata | Chordata | Chordata | Chordata | Chordata | | C | Mammalia | Mammalia | Mammalia | Mammalia | Mammalia | | O | Carnivora | Carnivora | Carnivora | Cetacea | Carnivora | | F | Ursidae | Felidae | Canidae | Delphinidae | Canidae | | G | Ursus | Felis | Canis | Orcinus | Canis | | S | Ursus arctos | Felis catus | Canis familiaris | Orcinus orca | Canis lupus |

PLANT KINGDOM
Plants, also called green plants (Viridiplantae in Latin), are living organisms of the kingdom Plantae including such multicellular groups as flowering plants, conifers, ferns and mosses, as well as, depending on definition, the green algae, but not red or brown seaweeds like kelp, nor fungi or bacteria.

ANIMAL KINGDOM
Animals are multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. All animals must ingest other organisms or their products for sustenance.

Broad classification of Kingdom Animalia based on common fundamental features

1. Symmetry
Animals can be categorised on the basis of their symmetry. Sponges are mostly asymmetrical, i.e., any plane that passes through the centre does not divide them into equal halves.

(a) Radial symmetry

(b) Bilateral symmetry

2. Diploblastic and Triploblastic Organization

Animals in which the cells are arranged in two embryonic layers, an external ectoderm and an internal endoderm, are called diploblastic animals, e.g., coelenterates. An undifferentiated layer, mesoglea, is present in between the ectoderm and the endoderm.

Figure 4.2 Showing germinal layers : (a) Diploblastic (b) Triploblastic
Those animals in which the developing embryo has a third germinal layer, mesoderm, in between the ectoderm and endoderm, are called triploblastic animals (platyhelminthes to chordates, Figure 4.2b).

Figure 4.3 Diagrammatic sectional view of : (a) Coelomate (b) Pseudocoelomate (c) Acoelomate

PHYLUM ANIMALIA

1. PHYLUM – PORIFERA
Members of this phylum are commonly known as sponges. They are generally marine and mostly asymmetrical animals (Figure 4.5). These are primitive multicellular animals and have cellular level of organisation.

Figure 4.5 Examples of Porifera : (a) Sycon (b) Euspongia (c) Spongilla

2. PHYLUM – COELENTERATA (CNIDARIA)
They are aquatic, mostly marine, sessile or free-swimming, radially symmetrical animals. The name cnidaria is derived from the cnidoblasts or cnidocytes (which contain the stinging capsules or nematocytes) present on the tentacles and the body. Cnidoblasts are used for anchorage, defense and for the capture of prey. Cnidarians exhibit tissue level of organisation and are diploblastic.

Examples: Physalia (Portuguese man-of-war), Adamsia (Sea anemone), Pennatula (Sea-pen), Gorgonia (Sea-fan) and Meandrina (Brain coral).

3. PHYLUM – CTENOPHORA
Ctenophores, commonly known as sea walnuts or comb jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organisation. The body bears eight external rows of ciliated comb plates, which help in locomotion (Figure 4.8).

Examples: Pleurobrachia and Ctenoplana.

4. PHYLUM – PLATYHELMINTHES
They have dorso-ventrally flattened body, hence are called flatworms. These are mostly endoparasites found in animals including human beings. Flatworms are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation.

Examples: Taenia (Tapeworm), Fasciola (Liver fluke).

5. PHYLUM – ASCHELMINTHES
The body of the aschelminthes is circular in cross-section, hence, the name roundworms. They may be freeliving, aquatic and terrestrial or parasitic in plants and animals. Roundworms have organ-system level of body organisation. They are bilaterally symmetrical, triploblastic and pseudocoelomate animals.

Examples : Ascaris (Round Worm), Wuchereria (Filaria worm), Ancylostoma (Hookworm).

6. PHYLUM – ANNELIDA
They may be aquatic (marine and fresh water) or terrestrial; free-living, and sometimes parasitic. They exhibit organ-system level of body organisation and bilateral symmetry. They are triploblastic, metamerically segmented and coelomate animals. Their body surface is distinctly marked out into segments or metameres and, hence, the phylum name Annelida (Latin, annulus : little ring).

Examples : Nereis, Pheretima (Earthworm) and Hirudinaria (Blood sucking leech).

7. PHYLUM – ARTHROPODA
This is the largest phylum of Animalia which includes insects. Over two-thirds of all named species on earth are arthropods. They have organ-system level of organisation. They are bilaterally symmetrical, triploblastic, segmented and coelomate animals. The body of arthropods is covered by chitinous exoskeleton. The body consists of head, thorax and abdomen. They have jointed appendages (arthros-joint, poda-appendages).

Examples: Economically important insects – Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect)

Vectors – Anopheles, Culex and Aedes (Mosquitoes)

Gregarious pest – Locusta (Locust) Living fossil – Limulus (King crab).

Figure 4.12 Examples of Arthropoda : (a) Locust (b) Butterfly (c) Scorpion (d) Prawn

8. PHYLUM – MOLLUSCA
This is the second largest animal phylum. Molluscs are terrestrial or aquatic (marine or fresh water) having an organ-system level of organisation. They are bilaterally symmetrical, triploblastic and coelomate animals. Body is covered by a calcareous shell and is unsegmented with a distinct head, muscular foot and visceral hump.

Examples of Mollusca : (a) Pila (b) Octopus

They are usually dioecious and oviparous with indirect development.
Examples: Pila (Apple snail), Pinctada (Pearl oyster), Sepia (Cuttlefish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea- hare), Dentalium (Tusk shell) and Chaetopleura (Chiton).

9. PHYLUM – ECHINODERMATA
These animals have an endoskeleton of calcareous ossicles and, hence, the name Echinodermata (Spiny bodied). All are marine with organ-system level of organisation. The adult echinoderms are radially symmetrical but larvae are bilaterally symmetrical. They are triploblastic and coelomate animals.

Examples: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber) and Ophiura (Brittle star).

Examples of Echinodermata : (a) Asterias (b) Ophiura

10. PHYLUM – HEMICHORDATA
Hemichordata was earlier considered as a sub-phylum under phylum Chordata. But now it is placed as a separate phylum under non-chordata. This phylum consists of a small group of worm-like marine animals with organ-system level of organisation. They are bilaterally symmetrical, triploblastic and coelomate animals.

Examples: Balanoglossus and Saccoglossus.

11. PHYLUM – CHORDATA
Animals belonging to phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits (Figure 4.16). These are bilaterally symmetrical, triploblastic, coelomate with organ-system level of organisation. They possess a post anal tail and a closed circulatory system.

TABLE 4.1 Comparison of Chordates and Non-chordates | Chordates | Non-chordates | 1 | Notochord present | Notochord absent | 2 | Central nervous system is dorsal, hollow and single | Central nervous system is ventral, solid and double. | 3 | Pharynx perforated by gill slits. | Gill slits are absent. | 4 | Heart is ventral. | Heart is dorsal (if present). | 5 | A post-anal part (tail) is present. | Post-anal tail is absent. |

Phylum Chordata is divided into three subphyla: Urochordata or Tunicata , Cephalochordata and Vertebrata.

Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine. In Urochordata, notochord is present only in larval tail, while in Cephalochordata, it extends from head to tail region and is persistent throughout their life. Examples: Urochordata – Ascidia, Salpa, Doliolum; Cephalochordata – Branchiostoma (Amphioxus or Lancelet).
The subphylum Vertebrata is further divided as follows:

11.1 CLASS – CYCLOSTOMATA
All living members of the class Cyclostomata are ectoparasites on some fishes. They have an elongated body bearing 6-15 pairs of gill slits for respiration. Cyclostomes have a sucking and circular mouth without jaws.

Examples: Petromyzon (Lamprey)- a jawless vertebrate; and Myxine (Hagfish).

11.2 CLASS – CHONDRICHTHYES
They are marine animals with streamlined body and have cartilaginous endoskeleton. Mouth is located ventrally. Notochord is persistent throughout life. Gill slits are separate and without operculum (gill cover). The skin is tough, containing minute placoid scales. Teeth are modified placoid scales which are backwardly directed. Their jaws are very powerful. These animals are predaceous. Due to the absence of air bladder, they have to swim constantly to avoid sinking.

Example of Cartilaginous fishes : (a) Scoliodon (b) Pristis

Examples: Scoliodon (Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray).

11.3 CLASS – OSTEICHTHYES
It includes both marine and fresh water fishes with bony endoskeleton. Their body is streamlined. Mouth is mostly terminal (Figure 4.20). They have four pairs of gills which are covered by an operculum on each side. Skin is covered with cycloid/ctenoid scales. Air bladder is present which regulates buoyancy. Heart is two-chambered (one auricle and one ventricle). They are cold-blooded animals. Sexes are separate. Fertilisation is usually external. They are mostly oviparous and development is direct.

Examples: Marine – Exocoetus (Flying fish), Hippocampus (Sea horse); Freshwater – Labeo (Rohu), Catla (Katla), Clarias (Magur); Aquarium – Betta (Fighting fish), Pterophyllum (Angel fish).

11.4 CLASS – AMPHIBIA
As the name indicates (Gr., Amphi : dual, bios, life), amphibians can live in aquatic as well as terrestrial habitats. Most of them have two pairs of limbs. Body is divisible into head and trunk. Tail may be present in some. The amphibian skin is moist (without scales). The eyes have eyelids. A tympanum represents the ear. Alimentary canal, urinary and reproductive tracts open into a common chamber called cloaca which opens to the exterior. Respiration is by gills, lungs and through skin. The heart is three- chambered (two auricles and one ventricle). These are cold-blooded animals. Sexes are separate. Fertilisation is external. They are oviparous and development is indirect.

Examples: Bufo (Toad), Rana (Frog), Hyla (Tree frog), Salamandra (Salamander), Ichthyophis (Limbless amphibia).

11.5 CLASS – REPTILIA
The class name refers to their creeping or crawling mode of locomotion (Latin, repere or reptum, to creep or crawl). They are mostly terrestrial animals and their body is covered by dry and cornified skin, epidermal scales or scutes. They do not have external ear openings. Tympanum represents ear. Limbs, when present, are two pairs. Heart is usually three-chambered, but four-chambered in crocodiles. Reptiles are poikilotherms. Snakes and lizards shed their scales as skin cast. Sexes are separate. Fertilisation is internal. They are oviparous and development is direct.

Examples: Chelone (Turtle), Testudo (Tortoise), Chameleon (Tree lizard), Calotes (Garden lizard), Crocodilus (Crocodile), Alligator (Alligator). Hemidactylus (Wall lizard), Poisonous snakes – Naja (Cobra), Bangarus (Krait), Vipera (Viper).

11.6 CLASS – AVES
The characteristic features of Aves (birds) are the presence of feathers and most of them can fly except flightless birds (e.g., Ostrich). They possess beak. The forelimbs are modified into wings. The hind limbs generally have scales and are modified for walking, swimming or clasping the tree branches. Skin is dry without glands except the oil gland at the base of the tail. Endoskeleton is fully ossified (bony) and the long bones are hollow with air cavities (pneumatic). The digestive tract of birds has additional chambers, the crop and gizzard. Heart is completely four- chambered. They are warm-blooded (homoiothermous) animals, i.e., they are able to maintain a constant body temperature. Respiration is by lungs. Air sacs connected to lungs supplement respiration. Sexes are separate. Fertilisation is internal. They are oviparous and development is direct.

Examples : Corvus (Crow), Columba (Pigeon), Psittacula (Parrot), Struthio (Ostrich), Pavo (Peacock), Aptenodytes (Penguin), Neophron (Vulture).

11.7 CLASS – MAMMALIA
They are found in a variety of habitats – polar ice caps, deserts, mountains, forests, grasslands and dark caves. Some of them have adapted to fly or live in water. The most unique mammalian characteristic is the presence of milk producing glands (mammary glands) by which the young ones are nourished. They have two pairs of limbs, adapted for walking, running, climbing, burrowing, swimming or flying. The skin of mammals is unique in possessing hair. External ears or pinnae are present. Different types of teeth are present in the jaw. Heart is four- chambered. They are homoiothermous. Respiration is by lungs. Sexes are separate and fertilisation is internal. They are viviparous with few exceptions and development is direct.

Examples: Oviparous-Or nithorhynchus (Platypus); Viviparous – Macropus (Kangaroo), Pteropus (Flying fox), Camelus (Camel), Macaca (Monkey), Rattus (Rat), Canis (Dog), Felis (Cat), Elephas (Elephant), Equus (Horse), Delphinus (Common dolphin), Balaenoptera (Blue whale), Panthera tigris (Tiger), Panthera leo (Lion).

The salient distinguishing features of all phyla under animal kingdom is comprehensively given in the Table 11

Bibiliography

Raven, Peter. Et al. 2013: Biology. 10th Ed. New York. Mc Graw-Hill Publihing

Gunstream, Stanley. 2011: Explorations in Basic Biology. 12th Ed. San Francisco USA. Benjamin Cummings Publishing

Michael L. McKinney. Et al. 2012: Environmental Science. 5th Ed. Massachusetts USA. Jones & Bartlett Learning

Freeman, Scott. Et al. 2013: Biological Science Vol. 1. 5th Ed. San Francisco USA. Benjamin Cummings Publishing

Timberlake, Karen. 2010: Basic Chemistry. 3rd Ed. New Jersey USA. Prentice Hall

Ditan, Carolina. 2010: Earth Sciences. Manila Philippines. National Book Store

Barreiro, Concha. Et al. 2008: Essential Natural Science 1. Miami, Florida USA. Santillana Publishing

Wikipedians. 2013: Natural Science. Mainz, Germany. Pediapress