PCAT Biological 4

Question 1

A mutation that converts a codon to a stop codon is best described as a:

Accepted Answer

Nonsense mutation

Answer

A nonsense mutation changes an amino acid codon to a premature stop codon, resulting in a truncated, usually nonfunctional protein.

Question 2

Which of the following is an example of negative feedback in the human body?

Accepted Answer

High blood glucose triggering insulin release to lower glucose

Answer

Insulin release in response to high blood glucose reduces glucose levels, which then signals decreased insulin release—a classic negative feedback loop.

Question 3

Which of the following correctly pairs an organelle with its function?

Accepted Answer

Peroxisome — breakdown of fatty acids and detoxification of H2O2

Answer

Peroxisomes contain oxidative enzymes for fatty acid beta-oxidation and catalase to decompose the resulting hydrogen peroxide.

Question 4

What is the significance of the ABO blood group system in pharmacology and medicine?

Accepted Answer

Mismatched transfusions trigger complement-mediated hemolysis

Answer

Transfusing incompatible ABO blood types causes recipient antibodies to activate complement, lysing donor red blood cells and potentially causing fatal hemolytic transfusion reactions.

Question 5

Which property of DNA allows it to serve as a template for its own replication?

Accepted Answer

Complementary base pairing between antiparallel strands

Answer

Complementary base pairing (A-T, G-C) between antiparallel strands means each strand can serve as a precise template for synthesizing a new complementary strand.

PCAT - Pharmacy College Admission Test Practice Test

PCAT - Pharmacy College Admission Test Practice Test

PCAT Biological 4