Natural selection operates on the _______ of an individual organism.
Stabilizing selection acts to _________ in a species' population.
1. elaborate new traits
2. alter traits
3. push for directional change
4. maintain a certain phenotype
Gene flow is
1. the migration of species populations to new areas
2. the exchange of genes during fertilization
3. mating between close relatives
4. the movement of genes between species populations
Genetic drift is
1. random changes in gene frequency in a population
2. generational fluctuations in gene frequencies that produce no effect
3. changes due to interbreeding with other species populations
4. the effect of mutations as they spread through neighbouring populations
Genetic drift is most powerful in
1. changing environments
2. small populations
3. large populations
4. stable environments
The concept of genetic bottlenecks includes which of the following?
1. a loss of genetic diversity in descendent populations
2. extensive gene flow
3. sharing of genetic material between two populations
4. increased ability to resist new diseases
Which statement most accurately reflects what population geneticists refer to as "fitness"?
1. Fitness is the measure of an organism's adaptability to various habitats.
2. Fitness reflects the number of mates each individual of the population selects.
3. Fitness refers to the relative health of each individual in the population.
4. Fitness is a measure of the contribution of a genotype to the gene pool of the next generation.
Organisms that are least likely to experience extinction over the long term are most likely to be found in _______________.
1. areas inhabited by humans
2. very stable habitats
Which one of the following would cause the Hardy-Weinberg principle to be inaccurate?
1. The size of the population is very large.
2. Individuals mate with one another at random.
3. Natural selection is present.
4. There is no source of new copies of alleles from outside the population.
Which one of the following populations would most quickly lead to two groups with few shared traits?
1. a population with disruptive selection
2. a population with directional selection
3. a population with stabilizing selection
4. a population with no selection