AP Biology practice exam 2017

Two populations of a species of squirrel are geographically isolated from each other. Although they have the same population density, on 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 two populations will be equally affected, because the ability to trigger an immune response is randomly distributed among all squirrels of that species.

• The larger population will be less affected by the disease than will the smaller population, because the mutation rate of the larger population is higher than the mutation rate of the smaller population

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

• The smaller population will be less affected than will the larger population, because the smaller population exhibits more genetic drift than the larger population exhibits

Mitochondria are found in most eukaryotic cells and contain their own DNA and Ribosomes that are similar to those typical of many prokaryotic cells. Which of the following statements is justified by these observations?

• The mitochondrion is the only location in which eukaryotic cells can synthesize ATP

• An ancestral cell most likely engulfed an aerobic prokaryote in a relationship that provided beneficial for both cells

• Mitochondrial membranes provide abundant surfaces areas for for reactions because of the infoldings called cristae

• The mitochondrion plays a role in resperation, but it also stores the cell's extra mRNA

Sickle-cell 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 it the most likely cause of sickle-cell anemia?

• A single base-pair substitution in the gene encoding the beta subunit

• A single base-pair insertion in the gene encoding the beta subunit

• A single base-pair deletion in the gene encoding the beta subunit

• A translocation of DNA from one chromosome to another

$

$