ap bio final review

Within a forest ecosystem, there is a large amount of diversity among members of a warbler species. Of the following stages of meiosis illustrated for a typical cell, which contributes most to diversity among the warblers?

2 Xs on top and 2 on bottom

Gregor Mendel's pioneering genetic experiments with pea plants occurred before the discovery of the structure and function of chromosomes. Which of the following observations about inheritance in pea plants could be explained only after the discovery that genes may be linked on a chromosome?

Most offspring of a given cross have a combination of given traits that is identical to that of either one parent or the other - When two genes are close together on the same chromosome, they do not assort independently and are said to be linked.

Eye pigment in a particular strain of fly is determined by two genes. An autosomal gene that controls the color of the pigments in the eye has two alleles: a dominant allele (R) that results in red eyes and a recessive allele (r) that results in sepia eyes. A sex-linked gene that controls the expression of the colored pigments also has two alleles: a dominant allele (T) that allows for expression of the colored pigments and a recessive allele (t) that does not allow for expression of the colored pigments. Individuals without a T allele have white eyes regardless of the alleles of other eye-color genes. Which of the following represents a cross between a white-eyed female and a red-eyed male?

RrXtXt X RrXTY

Scientists conducted a test of two alleles for fur color in a population of small mammals over a period of twenty years, Their results showed that the original population expressed one allele for fur color and the population twenty years later showed expression of the other allele. This changed the phenotype from brown to gray. Which of the following statements best describes this shift in the population?

The field was composed primarily of light-colored soil and little vegetation, affording gray mice protection from predators.

Two populations of a species of squirrel are geographically isolated from each other. Although they have the same population density, one population is significantly larger in number than the other. A new bacterial disease, which is easily spread and extremely virulent, affects both populations at the same time. Which of the following is the best prediction of how the new disease will affect the two populations?

The smaller population will be more affected than the larger population, because the smaller population has less genetic variation than the larger population has.

A genetic counselor is consulted by a young man who is worried about developing Huntington's disease, an inherited disorder caused by a dominant allele of a single gene. The young man explains that his cousin was recently diagnosed with Huntington's disease, and the news has caused him to consider his own risk of developing the disorder. Which of the following questions will best help the genetic counselor to evaluate the risk of the young man developing Huntington's disease and transmitting it to his children?

Were your parents or grandparents ever diagnosed with Huntington's disease?

Sickle-cell anemia is associated with a mutation in the gene encoding the beta subunit of hemoglobin that results in a change from glutamic acid to valine at position 6. All other amino acids are identical to a normal hemoglobin molecule. Based on the information above, which of the following mutations is the most likely cause of sickle-cell anemia?

a single base-pair substitution in the gene encoding the beta subunit

The difference in sparrow songs among sympatric species of sparrows is an example of

behavioral isolation

Latest theories have looked towards the first life being around volcanic structures called black smokers. These underwater vents, provide heat and a rich environment of minerals, including organic compounds. What type of organisms are most likely to have evolved first?

micropores *

The condition in which there are barriers to successful interbreeding between individuals of different species in the same community is referred to as

reproductive isolation