Kingdom Animalia Review
1. What are the major characteristics that distinguish animals from plants? (animals are motile, no cell wall, heterotrophic)
2. Why is it not sufficient to classify animals simply as multicellular heterotrophs? (does not exclude fungi)
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 to evolve 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 in sponge)
5. As animals became more complex, why was the development of a coelom important? (space for organs)
6. Explain why animals with radial symmetry show no signs of cephalization. (some encounter environment 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 capable of sexual reproduction)
9. Why is it helpful for an organism to be able to reproduce both sexually and asexually? (sex - genetic diversity; asexual - don’t 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, branching gut)
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 of repeated 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? (carry more 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 - highly cephalized)
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 satisfy higher oxygen requirements)
20. How is the closed circulatory system an advantage to cephalopods? (active swimmers need more energy)
21. Why does the presence of an exoskeleton require the presence of jointed appendages? (to enable movement)
22. What are the advantages and disadvantages of an exoskeleton? (adv - protection; disadv - heavy, must molt)
23. What factors limit the size of the insects? (bulk of exoskeleton (especially for flying), lack of strength of exoskeleton, inefficient open circulatory system, limitation of trachea to deliver gases to large volume of cells)
24. What is a tracheal respiratory system? Why is it an advantage? (branching; distribute O2 to more cells). 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 on water - wider habitats; more complex heart - endothermy; better cerebrum - complex behaviour and learning)
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 a higher blood pressure)
28. Why are amphibians considered to be transitional between fishes and terrestrial vertebrates? (life split between 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 to breathe)
31. State the advantage and disadvantage of using the skin as a respiratory surface. (extra surface area for breathing; 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? (oxygenated and deoxygenated blood mix in the ventricle)
34. Why did the development of the amniotic egg require animals to use internal fertilization? (shell prevents sperm reaching egg)
35. How did the amniotic egg allow reptiles to dominate the terrestrial environment? (the structures provide a self-contained, water-proof environment for the embryo)
36. Why do organisms which display internal fertilization not produce large numbers of eggs? (when gametes 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 oxygenated and 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 to best 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 a disadvantage)
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 allow continuous air flow through lungs)
46. What are the advantages of being an endotherm? (live in cold climate, no need to wait for ambient temperature 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)