10: evolution: species

Question 1

___________is the original source of new alleles

Answer 1

Mutation is the original source of new alleles

Question 2

What is required for evolution to occur in a population?

Answer 2

Genetic diversity is needed for evolution to occur in a population.

Question 3

Match the modes of natural selection with their best descriptions

a. eliminates extreme forms of a trait
b. eliminates midrange forms of a trait
c. shifts phenotypes in one direction

Answer 3

a) Stabilising
b) Disruptive
c) Directional

Question 4

The persistence of the sickle cell allele at high frequency in a population is an example of _____

Answer 4

The persistence of the sickle cell allele at high frequency in a population is an example of balanced polymorphism.

Question 5

_____ among populations can keep them similar to one another.

Answer 5

Gene flow among populations can keep them similar to one another.

Question 6

After fire devastates all of the trees in a wide swath of forest, populations of a species of tree-dwelling frog
on either side of the burned area diverge to become separate species. This is an example of __________ .

Answer 6

an example of disruptive evolution.