PCAT Biology 4

Question 1

Which type of epithelium lines the inner surface of blood vessels?

Accepted Answer

Simple squamous epithelium

Answer

Simple squamous epithelium (endothelium) lines blood vessels, allowing efficient diffusion and forming a smooth surface that reduces friction.

Question 2

In the lac operon of E. coli, what role does the repressor protein play in the absence of lactose?

Accepted Answer

It blocks the operator preventing transcription

Answer

In the absence of lactose (the inducer), the repressor binds the operator sequence and prevents RNA polymerase from transcribing the structural genes.

Question 3

Which phase of mitosis is characterized by chromosomes aligning at the cell's equatorial plate?

Accepted Answer

Metaphase

Answer

During metaphase, chromosomes align at the metaphase plate (cell equator) with spindle fibers attached to each sister chromatid's kinetochore.

Question 4

Which hormone is produced by the posterior pituitary and triggers uterine contractions during labor?

Accepted Answer

Oxytocin

Answer

Oxytocin, released from the posterior pituitary, stimulates uterine smooth muscle contractions during labor via a positive feedback mechanism.

Question 5

Which ecological relationship benefits one organism while neither harming nor helping the other?

Accepted Answer

Commensalism

Answer

Commensalism is a relationship where one organism benefits (+) while the other is unaffected (0), such as barnacles living on whale skin.

PCAT - Pharmacy College Admission Test Practice Test

PCAT - Pharmacy College Admission Test Practice Test

PCAT Biology 4