Question

1. humans are causing extinction in which ways?

a. by over hunting animals for food or products.
b. by destroying the natural habitat of species.
c. by polluting the environments of the world.
d. all of the above.

1. mass extinction is best defined as....

a. complete loss or death of a species
b. an abnormally large amount of species dying out simultaneously or within a short period of time
c. change in global or regional climate patterns
d. change in climate during which glaciers covered much of the earth

1. natural selection is not the only mechanism of evolution. which of the following mechanisms is illustrated by individuals immigrating and/or emigrating between populations?

a. genetic drift/small population
b. gene flow
c. sexual selection/non - random mating
d. mutations

1. the lamprey possesses a vertebral column but lacks jaws. this means the common ancestor of the lamprey and the tuna must have possessed which feature(s)?

a. jaws only
b. four walking legs
c. vertebral column only
d. both jaws and vertebral column

1. which of the following characteristics is a unique shared derived character for just the turtle and leopard lineage?

a. vertebral column
b. hair
c. four walking legs
d. amniotic egg

1. which of the following are more closely related?

a. lancelet and tuna
b. turtle and tuna
c. leopard and tuna
d. salamander and turtle

Explanation:

• Question 10: Over - hunting (a), habitat destruction (b), and pollution (c) are all human - caused factors leading to extinction. So, all the options are correct.
• Question 11: Mass extinction is defined as an abnormally large amount of species dying out simultaneously or within a short period of time. Option a is the definition of extinction of a single species, option c is about climate change, and option d is about an ice - age like climate change.
• Question 12: Gene flow is the transfer of genes from one population to another due to immigration and/or emigration. Genetic drift (a) is due to random sampling in small populations, sexual selection (c) is about mating preferences, and mutations (d) are changes in the DNA sequence.
• Question 13: Since the lamprey has a vertebral column (a characteristic of vertebrates) and the tuna also has a vertebral column (and the lamprey lacks jaws which is a derived characteristic), the common ancestor must have had a vertebral column.
• Question 14: The amniotic egg is a shared derived character for the turtle and leopard lineage. The vertebral column (a) is more basal, hair (b) is only for mammals (leopard), and four walking legs (c) are also more basal (salamander also has them).
• Question 15: Salamander and turtle share a more recent common ancestor compared to the other pairs. Looking at the cladogram, they are closer on the branching pattern.

Answer:

1. d. All of the above
2. b. An abnormally large amount of species dying out simultaneously or within a short period of time
3. b. Gene flow
4. c. Vertebral column only
5. d. Amniotic egg
6. d. Salamander and Turtle