Kingdom Animalia Review

1. What are the major characteristics that distinguish animals from plants? (animals are motile, no cellwall, heterotrophic)

2. Why is it not sufficient to classify animals simply as multicellular heterotrophs? (does not excludefungi)

3. What conclusions can be drawn from the observation that almost all animals undergo similar development from zygote to blastula to gastrula? (probably share common ancestors because unlikely toevolve independently)

4. A student submits a diagram of an embryo with the three germ layers labelled. The title reads “Diagram of sponge embryo.” Do you mark it right or wrong? Explain. (Wrong - no germ layers insponge)

5. As animals became more complex, why was the development of a coelom important? (space fororgans)

6. Explain why animals with radial symmetry show no signs of cephalization. (some encounterenvironment from all sides; some non-motile)

7. Is your head anterior or posterior to your arms? (anterior) Describe the location of your arms in relation to your shoulders. (lateral)

8. Why are sponges classified as part of the animal kingdom? (multicell, eukaryotic, heterotrophs capableof sexual reproduction)

9. Why is it helpful for an organism to be able to reproduce both sexually and asexually? (sex - geneticdiversity; asexual - dont need a partner)

10. How is cephalization an evolutionary advantage? (can sense environment ahead)

11. How has the digestive system of planaria been improved over that of the jellyfish? (organs, branchinggut)12. How does an animal in the phylum Platyhelminthes obtain oxygen? Why is this sufficient for these organisms? (absorb through body cells; they are small)

13. In a parasitic worm, why would it be useful to be hermaphroditic? (as the only individual in a host,being a hermaphrodite is the only way for sexual reproduction)

14. How have the digestive systems of the roundworm and segmented worm been improved compared to that of flatworms? (one-way, food can be processed continually; specialized organs in segmented worms)

15. What is meant by segmentation? How is segmentation an evolutionary advantage? (body made ofrepeated sections; advantage because segments can be specialized without affecting others)

16. Some organisms have a circulatory system with blood but the blood has no hemoglobin. What is the function of the blood in these organisms? Why is it an advantage to have hemoglobin in the blood? (carrymore oxygen so organism can be larger and more active)

17. Using cephalization as a basis, list the molluscs in order from oldest to most recent and explain your reasoning. (bivalvia - no cephalization, gastropoda - not always obvious, cephalopoda - highlycephalized)

18. Give a possible reason why bivalves have not tended toward cephalization. (largely sessile)

19. Why have more complex organisms such as molluscs had to develop gills? (diffusion cannot satisfyhigher oxygen requirements)

20. How is the closed circulatory system an advantage to cephalopods? (active swimmers need moreenergy)

21. Why does the presence of an exoskeleton require the presence of jointed appendages? (to enablemovement)

22. What are the advantages and disadvantages of an exoskeleton? (adv - protection; disadv - heavy, mustmolt)

23. What factors limit the size of the insects? (bulk of exoskeleton (especially for flying), lack of strengthof exoskeleton, inefficient open circulatory system, limitation of trachea to deliver gases to large volumeof cells)

24. What is a tracheal respiratory system? Why is it an advantage? (branching; distribute O₂ to morecells). Why is this especially important for flying insects? (need more oxygen for flight; highly branched)

25. Why are bilateral symmetry, muscle segmentation and the presence of a coelom not sufficient to classify an organism as a chordate? (also present in arthropods and annelids)

26. State the evolutionary trends in the vertebrates and state the importance of each. (less dependant onwater - wider habitats; more complex heart - endothermy; better cerebrum - complex behaviour andlearning)

27. How is circulation through two circuits (as in amphibians, birds, and mammals) superior to circulation through just one (as in the fishes)? (heart can pump blood to the lungs and body separately, allowing ahigher blood pressure)

28. Why are amphibians considered to be transitional between fishes and terrestrial vertebrates? (life splitbetween water and land)

29. What adaptations allowed amphibians to colonize the land? (legs and lungs)

30. What features of the frog restrict them to living near the water? (lay eggs in water, keep skin moist tobreathe)

31. State the advantage and disadvantage of using the skin as a respiratory surface. (extra surface area forbreathing; must keep it moist or die)

32. The blood that enters the lungs of an amphibian has relatively (more*, less) oxygen than the blood that enters the gills of a fish. The reason for this is that the blood that goes from an amphibian's heart to its lungs is _____ (a mixture of oxygenated and deoxygenated). The blood that is carried to all organs of a fish's body is _____ (oxygenated). The blood that is carried to the fish's gills is _____ (deoxygenated). The blood that is carried to the organs of an amphibian is (mixed).

33. Why is the three chambered amphibian heart not as efficient as a four chambered heart? (oxygenatedand deoxygenated blood mix in the ventricle)

34. Why did the development of the amniotic egg require animals to use internal fertilization? (shellprevents sperm reaching egg)

35. How did the amniotic egg allow reptiles to dominate the terrestrial environment? (the structuresprovide a self-contained, water-proof environment for the embryo)

36. Why do organisms which display internal fertilization not produce large numbers of eggs? (whengametes are held internally, fertilization is more likely)

37. What is the major protein component in reptilian skin? (keratin) What does this suggest about the evolution of birds and mammals? (feathers and nails both contain keratin)

38. What could happen to a reptile that could not find any shade? (overheat)

39. How does the reptilian heart differ from the amphibian heart? (reptile - partially separates oxygenatedand deoxygenated blood)

40. How does the limb position of reptiles differ from that of amphibians and mammals. (amphibians -limbs straight out from body; reptiles - limbs out at an angle and down; mammals - most below body tobest support weight)

41. Many reptiles have clawed toes while amphibians do not. How might this be an advantage to them? (traction on land)

42. Mammals usually eat several times a day. Why are reptiles often able to go long periods without eating? (ectotherms - lower need for food)

43. Suppose that a mutation occurred, causing a bird’s vertebrae to extend into a tail. Is it likely that such a mutation would be preserved by the environment? Explain. (No. A heavy tail would be adisadvantage)

44. People say that someone with a small appetite “eats like a bird.” Why is this expression inaccurate? (birds eat a large amount relative to their weight; digestion is rapid to minimize weight)

45. How has the respiratory system of birds developed over that of other vertebrates? (air sacs allowcontinuous air flow through lungs)

46. What are the advantages of being an endotherm? (live in cold climate, no need to wait for ambienttemperature to become active)

47. State the relationship between the time a young mammal spends with it's parent and the complexity of it's behaviour as an adult. (more time with parent - more complex behaviour)

48. Imagine that you are on a fun ski weekend when you discover a frozen specimen of a prehistoric terrestrial vertebrate. Because you have an unquenchable thirst for knowledge and understanding, you absolutely MUST classify it. What characteristics would you examine to place the specimen in the correct class? (skeleton, heart, outer covering)

49. The muscle that supports the internal organs of humans seems to be designed for an organism that walks on four legs. What does this suggest? (evolved from an ancestor which did not walk upright)