Biology II Lecture Quiz 1

Population genetics is the study of:

A. How selective forces change the allele frequencies in a population over time

When males and females of a population look or act differently, it is referred to as _________.

A. Sexual dimorphism

What is assortative mating?

A. When individuals mate with those who are similar to themselves

A(n) _________ neuron has one axon and one dendrite extending directly from the cell body

B. Bipolar

Which of the following evolutionary forces can introduce new genetic variation into a population?

B. Mutation and gene flow

Glia that provide myelin for neurons in the brain are called _________.

B. Oligodendrocytes

After an action potential, the opening of additional voltage-gated _______ channels and the inactivation of sodium channels, cause the membrane to return to its resting membrane potential.

B. Potassium

For a neuron to fire an action potential, its membrane must reach ________.

B. The threshold of excitation

Neurons contain __________, which can receive signals from other neurons

C. Dendrites

Which type of selection results in greater genetic variance in a population?

C. Diversifying selection

What is the term for protein channels that connect two neurons at an electrical synapse?

C. Gap junction protein

When closely related individuals mate with each other, or inbreed, the offspring are often not as fit as the offspring or two unrelated individuals. Why?

C. Inbreeding can bring together rare, deleterious mutation that lead to harmful phenotypes

What is the difference between micro- and macroevolution?

C. Microevolution describes the evolution of organisms in populations, while macroevolution describes the evolution of species over long periods of time

When male lions reach sexual maturity, they leave their group in search of a new pride. This can alter the allele frequencies of the population through which of the following mechanisms?

C. gene flow

Which of the following populations is not in Hardy-Weinberg equilibrium?

D. A population undergoing natural selection

One of the original Amish colonies rose from a ship of colonists that came from Europe. The ship's captain, who had polydactyly, a rare dominant trait, was one of the original colonists. Today, we see a much higher frequency of polydactyly in the Amish population. This is an example of:

D. Genetic drift and founder effect. Both b and c

What is a cline?

D. Gradual geographic variation across an ecological gradient

The good genes hypothesis is a theory that explains what?

D.Why individuals of one sex develop impressive ornamental traits