Question

48. Provide evidence that amphibians are both terrestrial and aquatic animals. (4)

49. Which structure was most important in allowing reptiles to break completely free of water in comparison to amphibians?

a. better adapted eyes

b. an amniotic egg

c. four chambered heart

d. claws

50. Which of the following groups of vertebrates are endothermic (circle all that apply).

a. ‘classic’ reptiles (snakes, turtles, alligators)

b. birds

c. mammals

d. amphibians

e. fish

51. What is an advantage of being endothermic? (2)

52. What is a disadvantage of being endothermic? (2)

53. A group of mammals that lays eggs and do not have nipples, babies suck milk from the hairs on their mother’s chest.

a. monotremes

b. marsupials

c. eutherians

54. A group of mammals that have a placenta that provides oxygen and nutrients to embryos in the uterus.

a. monotremes

b. marsupials

c. eutherians

55. A group of mammals that give birth after a short period of development. Females have a pouch where the young complete development.

a. monotremes

b. marsupials

c. eutherians

56. You are an evolutionary biologist studying human lineages. While digging at your current site, a mostly intact skull of a possible human ancestor is unearthed. After analysis in the lab, it is determined that the brain capacity of the organism was 800 cm³. Which genus would you place this organism in?

a. Australopithecus

b. Paranthropus

c. Homo

57. Complete the following classification for humans. (9 points)

Domain ______________________________________________________________________

Kingdom _____________________________________________________________________

Phylum _______________________________________________________________________

Subphylum ___________________________________________________________________

Class __________________________________________________________________________

Order _________________________________________________________________________

Family ________________________________________________________________________

Genus _________________________________________________________________________

Species ________________________________________________________________________

Answer 1

48. In order to live on land, amphibians replaced gills with another respiratory organ, the lungs. Other adaptations include Skin that prevents loss of water. Eyelids that allow them to adapt to vision outside of the water. Other adaptations include- being cold-blooded, having webbed feet for swimming, breathing through skin etc.

49b. An amniotic egg

The amniotic egg was an evolutionary invention that allowed the first reptiles to colonize dry land more than 300 million years ago. Fishes and amphibians must lay their eggs in water and therefore cannot live far from water. But the presence of amniotic egg allowed reptiles to lay their eggs nearly anywhere on dry land.

50. Birds, Mammals

Endotherm, so-called warm-blooded animals; that is, those that maintain a constant body temperature independent of the environment. The endotherms primarily include the birds and mammals.

51. One advantage of endothermy is that it gives endothermic animals greater stamina than ectothermic animals. Because of their faster metabolism, endothermic animals can quickly resupply muscles with energy and rapidly break down muscular waste products.

52. Being endothermic allows us to live in cooler areas and regulate our body temperatures to fight off infection. The downside, though, is that regulating body temperature is energetically costly, and warm-blooded animals need more food than cold-blooded ones.

53a. Monotremes

54c. Eutherians

55b. Marsupials

56c. Homo