more offspring so next generation will have more concentration of toxic. 2. Why is cancer a multicellular organism’s disease? Uncontrolled cell because they produce thousands of single cells and they produce new organisms. They divided constantly (have chance to produce new) 3. Explain the following sentence: “What cancer has on it side is mainly the astronomical number of chances it gets to achieve success against the immense odds.” Your answer should include an explanation of why cancer gets an “astronomical number of chances” and why there are such “immense odds.” Portions: they attack cells and then kill them. Anti cancer mechanisms, so cancer has to go through all of them. 4. What types of anti-cancer mechanisms exist in our bodies? Inseam 5. Is cancer a result of genetics? The environment? Viruses? Parasites? All of them 6. What is the p16 protein? What is the benefit of having the p16 protein? What is the drawback of the having this protein? Anticancer, it will attack any sells that replicate itself, but it makes us old (natural selection) 7. Why is Retinoblastoma so rare? Explain why it is unlikely that natural selection has selected against Retinoblastoma. Because we get it when we are before 5 years old. Retin cells stop dividing when we are 5 years old. Natural selection can not act with these cells because they are rare. 8. How has the FAS gene been important to human evolution? How does this gene affect cancer cells? FAS genes acids are important for brain development. Also, cancer use them to produce energy and to grow. 9. What is the “tug-of-war” that exists between pregnant mothers and their fetuses? How has this tug-of-war benefitted cancer cells? Umbilical cord Cancer takes these genes and use them. (From blood) 10. Explain why a defense against cancer does not have to eradicate the disease completely to be favored by natural selection. Has natural selection already selected against cancer? How do you know if it has or has not? Natural selection selects against cancer through age, so at late age the bodies might get cancer. (most cancers are in late ages). In addition, it does not replicate, and it has to postpone. Most people get it in production age. 11. Explain how are some reproductive cancers in women related to the number of menstrual cycles they have had during their lifetime. Because they need tons of energy. (prenatal control) LECTURE MATERIAL 1. What is an adaptation? A trait that allows an organism to live successfully in its environment. Also, it is a characteristic of an organism that has been favored by natural selection. Adaptations are traits that have been selected by natural selection. 2. What is camouflage? Animal look like things in environment (rock, twig, leaf) 3. What is mimicry? Animal uses colors and markings to look like another animal. 4. Unlike many animals, Xenophora gastropods are not naturally camouflaged (i.e. their genetics do not code for a naturally camouflaged body). In what unique way do they camouflage into their environment? They attach items found on the seafloor as a camouflage 5. In what unique way do Flatfish camouflage in with their environment? The surface of the fish facing away from the sea floor is pigmented, often serving to camouflage the fish, but sometimes with striking colored patterns. Some flatfish are also able to change their pigmentation to match the background 6. What types of organisms do some fly species mimic? Plants or flowers 7. What is a startle display? Why is it advantageous? It is hidden marks on the organism’s organs. Some butterflies have eye-shape wings. It is used to avoid predators. 8. Small eyespots on the wings of moths & butterflies have been shown to cause predators to bite at that part of moths/butterfly’s body. Why are these small eyespots actually advantageous for the moth/butterfly if they are causing a predator to bite at these spots? The small eyespots are intended to mimic the butterfly’ head, so it will escape very fast when the predator bite this places. 9. What do large eyespots on the wings of moths & butterflies mimic? It mimics the actual eyes of its predators, so they will be afraid from the butterfly. 10. What is that advantage of a pufferfish’s, an owl’s, and a frilled lizard’s startle display? The startle display makes them look more aggressive and bigger which make their predators scared. 11. What unusual startle display does a short-horned lizard exhibit? Its eyes get pressurized with blood, and they shoot the blood toward its predators. 12. What is an assassin bug? What does it prey on? Does it use camouflage or mimicry to catch its prey? It is a leaf bug which is born naked with sticky hairs, but they attach themselves, after visiting a termite nest, to the nest’s materials. Assassin bugs are predators of termites On a leaf, they don’t look camouflaged, but on the nest, they look and smell just like the nest. 13. Do stick insects, leaf insects, praying mantis’, and many species of grasshoppers and katydids illustrate camouflage or mimicry? Mimic 14. Why does natural selection select for “imperfect” adaptations? Because Adaptation is the outcome natural selection. 15. How is the recurrent laryngeal nerve in all tetrapods, especially the giraffe, and example of an imperfection? The nerve's route would have been direct in the fish-like ancestors of modern tetrapods, traveling from the brain, past the heart, to the gills (as it does in modern fish). Over the course of evolution, as the neck extended and the heart became lower in the body, the laryngeal nerve was caught on the wrong side of the heart. Natural selection gradually lengthened the nerve by tiny increments to accommodate, resulting in the circuitous route now observed 16. What makes ‘tinkering’ rather than ‘engineering’ a better analog for how natural selection works? 1- Natural selection has no plan (Whatever works survived, the better, the more offspring) 2- Natural selection modifies what already exists (engineers work from scratch) 17. What has been modified to produce the wings of a bat? Finger bones have been changed. Also, the skin on the wings. 18. What has been modified to produce poison glands in many amphibians? Its skin became like snakes to protect them from predators. 19. What has been modified to produce the trunk of an elephant? The upper lip and nose were attached together. 20. What is sexual dimorphism? Males and females of the same species differ in morphology. 21. In sexually dimorphic animals what are the typical differences between males & females? Consider characteristics such as color, flashiness, size, etc. Males: (More brightly colored – sport various adornments- more aggressive and competitive) . Among smaller organisms, when the sexes differ in size it is usually the females who are bigger. 22. How did sexually dimorphism likely evolve? Through sexual selection. 23. What is sexual selection? Why is it sometimes actually disadvantageous to an animal’s survival? Consider this with regards to frog/toads mating calls and run-away sexual selection in birds. It operates on characters that help organisms obtain mates. The might produce some sounds that make bats come and eat them. 24. How is mate choice involved in sexual selection? Which gender is usually doing the choosing? Power to charm the females Females usually choose. 25. What is intrasexual selection? How is it involved in sexual selection? In which gender does intrasexual selection usually take place? Power to conquer other males in battle Between males. 26. What is a lek? When males flock together on communal display ground. 27. In what unusual way do bowerbird males try to attract females? By building decorated and structured homes for females. 28. What is run-away sexual selection? Females choose males with distinctive trait. Offspring have exenterated trait (males) and preferences for that trait (females). Selection reinforces both traits and preferences. 29. What are sex roles? How have they evolved? Strategies employed by each sex to insure reproductive success. The typical sex roles have evolved via selection based on basic differences in reproductive biology. 30. How do the sex roles of females & males differ? Why do the sex roles between males & females differ? Females: choosy, discriminating Males: aggressive, competitive, flashy, less discriminating Differ: 1- Relative investment in reproduction (usually greater for females therefore females more choosy) 2- Reproductive Potential (usually greater for males therefore males more aggressive and competitive) 31. Female elephant seals and giraffes are not necessarily picky in terms of whom they will mate with. Males, however, display very specific sex roles that dictate which males will and will not get to mate – how so? 2- Reproductive Potential (usually greater for males therefore males more aggressive and competitive) 32. How do sex roles vary between monogamous vs. non-monogamous animals? Monogamous: (exhibit low-to-not sexual dimorphism / Have similar sex role) NON- monogamous: (highly sexually dimorphism/ sex-roles more common) 33. How many offspring do most male elephants seal have? Explain the extreme variation in reproductive success of male elephant seals. Since one male will fight to have a lot of females, the chance of having more offspring by the male is high. 34. Who will have more offspring over their lifetime: a male that mates will the same 10 females, or a females that mates with the same 10 males? Why? Assuming 10 children per woman, a man mated to 10 women has 10 times more children than a woman mated to 10 men. 35. Is mate choice hard-wired? – i.e. is there a genetic basis for it? It is generally hired-wired but some species have genetic bases for the mate choice 36. Gouldian Finches are not sexually dimorphic, yet they have three different colors heads that are possible. Which color head is the most common? the least common? Explain what is going on. Red head. Red is dominant to yellow, which is dominant to black. Red and black are sex-linked trait. Because birds have ZZ/Zw chromosomes, males can have two genes for red head, and females have only one red head. Yellow head is an autosomal recessive, but it expressed when the bird carry one copy of red color. As a result, red head birds produce offspring with red, yellow, or black color. Also, yellow head can produce the three colors. On the other hand, black head can produce only black color. 37. What are some species that exhibit sex role reversal? How has this reversal let to “cheating” in monogamous shorebirds? Black lemur and seahorses. Breed in high Arctic, and monogamy is typical. The ecological conditions led to selection for: males: strong attachment to eggs, and females: rapid recovery from egg-laying. Once these conditions exist, it levels the playing field, and sets the stage for cheating to evolve in females. 38. What is coevolution? Two types of coevolution were discussed in class: mutualism & parasitism. What is the difference between these two? Two or more unrelated species adapting to each other. Mutualism: interaction between individuals of different species that benefit both partners. Parasitism: relationship between organisms where one member benefit and the other is harmed. 39. Know the examples of mutualism (Ants & Bullhorn Acacia, Ants & Treehoppers) and parasitism (Wasps & Caterpillars, Snails & Flatworms, Insects & Fungi, Brood Parasites). Be able to explain how the relationships in these examples work. Bullhorn Acacia: insects & animals attempting to eat the plant’s foliage are met by a large number of fast, agile, highly-aggressive, stinging defenders! Ants: protein-lipids (food)/ nectar/ living space in thorns. Ants & Bullhorn Acacia: Treehoppers secrete “honeydew” (sugary liquid) that ants drink What do the ants do?
• patrol, drive off intruders
• carry to good feeding spots
• build small shelters
• store treehopper eggs in own nests
Wasps & Caterpillars: parasitic wasp grubs inside caterpillar host
Brood Parasites: cowbirds lay their eggs in their nests 40. What is the Geologic Time Scale? It is what the geologists developed as a model of the history life of Earth. Eons are the largest subdivision of geologic time. Eons are broken down into smaller units called Era. Today we are living in the Phanerozoic Eon and the Cenozoic Era. 41. When was the Hadean Eon? What characterized it? 4.56-3.8 Ga. Earth was bombarded by meteorites which prevented life from evolving. 42. What were early Earth conditions like? How do scientists know this? Earth was bombarded by meteorites. From the meteorites and because the moon is part from the earth and the moon has big holes that the earth now does not have it, and only has some remaining meteorites. 43. How was the moon formed? Mars-sized body collides with the earth. (it was a part from the earth and exploded) 44. What is the oldest known material on Earth? How old is
it? Zircon (4.4Ga) 45. How old is the Earth? Where do we get this age from? About 4.56 Ga From the old meteorites. 46. What is the first evidence for life on Earth? Isua, Greenland The fossils from rocks contain organic carbon. 47. How old are the Earth’s oldest fossils? What are they? How are they made? 3.5 Ga Cyanobacteria (prokaryotes) It obtains energy trough photosynthesis 48. What is the evidence for buildup of oxygen in the oceans? In the atmosphere? Where does this oxygen come from? Banded Iron Formation (BIFs) - lots of dissolved iron in oceans. - photosynthesis by bacteria produces oxugen. - iron combines with oxygen to form iron oxides. - When oceans waters become permanently oxygenated, BIFs no longer present. - free oxygen moves to atmosphere. 49. How old are the oldest eukaryotes? Why does it take them so long to evolve after prokaryotes? How did they evolve from prokaryotes? What is this theory called? What is the evidence for this? 2.0 Ga. It could not evolve before oxygen was a permanent component of seawater. Mitochondria & chloroplasts evolved from bacterial cells trapped inside other bacteria. Endosymbiosis. 1- size of the organelles = size of the bacteria. 2- organelles have their own double-members. 3- organelles have their own circular DNA, RNA, and Ribosome. 4- organelles have their own independent reproductive mechanisms. (like bacteria) 5- mitochondria and chloroplasts are susceptible to antibiotics 50. What is the name for the first group of multicellular organisms? How are they different than the multicellular life that arises in the Cambrian Explosion (i.e. at the very start of the Phanerozoic Eon and Paleozoic Era)? Ediacaran Biota Entirely soft bodied organisms 51. What is the Precambrian? What proportion of Earth’s history does it represent? Know the order that major events occurred (e.g. bacteria, oxygenation of oceans, etc.) during the Precambrian. Represents 87% of geological time Chemical signature of life (3.8 Ga) Prokaryotes (3.5 Ga) Eukaryotes (2.0 a) Multicellular Eukaryotes (600 Ma) Embryos (570 Ma) 52. What is the Phanerozoic? When does it start? What are the three Eras of the Phanerozoic? When the life has started 542 Ma 1- Paleozoic 2- Mesozoic 3- Cenozoic 53. What is the “Cambrian Explosion”? When the life started before about 540 Ma, and the explosion of animal happened. 54. Know the types of life that were most common during the Paleozoic & Mesozoic. Know the order that major events (e.g. evolution of groups of organisms) occurred during the Paleozoic & Mesozoic. Paleozoic: Trilobites in the seas and anomalocaris. (Asaphida- Lichida- Redlichiida) Paleozoic: Cambrian(Pikaia & jawless fishes)—Ordovician—Silurian(Land plants & jawed fishes)—Devonian (tetrapods)—Carboniferous—Permian Mesozoic : Pterosaurs and dinosaurs Mesozoic: Triassic—Jurassic—Cretaceous 55. What makes life moving from sea to land difficult? 1- structural support 2-dessication 3-tempreture extremes 4-respiration 5-reproduction 56. What are the first organisms to make their way on land? How are they different than the majority of their modern-day relatives? Plants. 1- small and simple 2- restricted to aqueous environment. 3- lack leaves, roots, and seeds. 4- spores. 57. What is the first type of animal on land? Arthropods 58. Why were arthropods so big ~300Ma? The oxygen level increased. 59. What caused the dramatic increase in oxygen levels in during the middle of the Paleozoic Era? There were a lot of plants that time which caused the photosynthesis to increase it 60. Who is Pikaia? It is a vertebrate lineage lived before 530 Ma (notochord) 61. What are the characteristics of the earliest fish? 1- jawless 2- are armored 3- no paired fins 4- have head shields. 62. What is the difference between a ray-fin & a lobe-fin fish? Lobe-fin: bony fish with lobed fins which are joined to the body by single bone( this evolved to legs) Ray-fin: skin supported by bony spins. 63. What is a tetrapod? Lobe-finned fishes which had four legs and moved from the water to the land. 64. What group of animals did amphibians evolve from? Lobe-finned fish 65. Who is Acanthostega? What are its characteristics? Type of amphibians that moved from the water. Tetrapod features (legs, feet, digits) & Fish-like features (tail fin, gills) 66. Who is Tiktaalik? What are its characteristics? The animal that came between lobe-finned fish and the tetrapods. Tetrapod characteristics (flexible neck, full of ribs to help breath and support body, and fins are limb-like which have shoulders, elbow, and wrist) Fish-like characteristics (fins, scale, and gills) 67. What are Pterosaurs? In what type of environment did they live? What did most species eat? What were their wings made out of? What bones supported their wings? How big were they? What is a homologous trait they share with other vertebrates? What is an analogous trait they share with other groups? – what other groups of animals share this trait? Not a dinosaurs, and winged lizard which lived from 220- 65 Ma. Near from seas, rivers, or lakes. They eat fish. Wings made of skin. They had 4 fingers and the wing was supported by the elongate 4th finger. Some of them were small and the others were huge sized. Homologous: the basic patterns of the bones Analogous: The wings (bats, birds, and some flies) 68. What are the three major trends in dinosaur evolution? 1- increase in size 2- herbivorous 3- quadrapedal 69. Mammals lived along with the dinosaurs – how were they different during the Mesozoic compared to today? dominate terrestrial ecosystems for 165 million years 70. What do mass death sites & trackways tell us about dinosaurs? That many species traveled in herds. 71. What does the preservation of skin tell us about dinosaurs? Why is the preservation of dinosaur skin so rare? most of them were plant eaters, thick Because when they died most of the skin were eaten or disattached from the body. 72. What do dinosaur eggs & nests tell us about dinosaurs? Some of them brooded their eggs like birds, there were more than one eggs and they were small