Marathon 4

Microevolution occurs __________ species. Speciation occurs __________ species

• within; between

• between; within

• between; between

• within, within

Rosie is a German shepherd in Boston, and Bruce is a golden retriever in Los Angeles. They will never meet one another. Which of the following is true of Rosie and Bruce?

• They are reproductively isolated.

• They are not reproductively isolated.

• They are not members of the same species.

• They are hybrids.

A definition of a species that uses primarily physical traits such as shape, size, and other features of anatomy uses the __________ species concept. This approach is often applied to categorizing fossils.

• biological

• ecological

• morphological

• phylogenetic

Sympatric speciation in animals usually occurs through __________ and __________.

• sexual selection; polyploidy

• geographic isolation; habitat differentiation

• sexual selection; self-fertilization

• habitat differentiation; sexual selection

When a horse and a donkey mate, they produce infertile hybrids called mules. This is a type of _________ barrier to the production of fertile offspring. According to the biological species concept, horses and donkeys belong to __________ species.

• prezygotic; different

• postzygotic; the same

• prezygotic; the same

• postzygotic; different

Two species of bird share a habitat along the Maine coast. One species is nocturnal, whereas the other is awake during the day. Which type of reproductive barrier, if any, exists between these species?

• temporal isolation

• mechanical isolation

• behavioral isolation

• habitat isolation

The sum of the frequencies of three alleles in a population always equals __________.

• 1

• 100%

• 1,000

• This is a variable number

Which sickle-cell-related allele has the greatest reproductive success in regions where malaria is a common disease?

• People who are heterozygous for the hemoglobin allele

• People who are homozygous for the sickle-cell allele

• All hemoglobin phenotypes have equal reproductive success.

• People who are homozygous for the normal hemoglobin allele

Human infants that are very heavy or very light at birth are less likely to survive than infants who weigh between 6 and 8 pounds. This is an example of which of the following?

• natural selection

• directional selection

• disruptive selection

• stabilizing selection

Which of the following statements about genetic drift is accurate?

• Genetic drift is more likely to have a major impact on small populations than on large populations.

• Genetic drift is a type of natural selection.

• Genetic drift is different from the founder effect.

• Genetic drift is more likely to have a major impact on large populations than on small populations.