GRE Subject Test: Biology : Understanding Reproductive Functions

Study concepts, example questions & explanations for GRE Subject Test: Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : Understanding Reproductive Functions

What is the purpose of the corpus luteum in females?

Possible Answers:

Release human chorionic gonadotropin in order to preserve the egg

Contain the egg prior to ovulation

Release hormones to stimulate menstruation

Release progesterone and estradiol following ovulation

Correct answer:

Release progesterone and estradiol following ovulation

Explanation:

The corpus luteum is formed from the remainder of the follicle following ovulation. The corpus luteum will release estradiol (estrogen) and progesterone in order to prepare for pregnancy. If pregnancy does not take place, the corpus luteum will degrade into the corpus albicans.

The follicle contains the egg prior to ovulation and releases it after stimulation by follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. Human chorionic gonadotropin (hCG) is the hormone responsible for maintaining the uterus and placenta during pregnancy, and is released by the uterus.

Example Question #1 : Other Reproductive Physiology

On the fourteenth day of the menstrual cycle, the pituitary gland releases a hormone which allows the ovary to release a matured egg. This egg is then swept into the fallopian tube. What phase of the menstrual cycle encompasses these events?

Possible Answers:

Menstrual phase

Follicular phase

Luteal phase

Vaginal phase

Ovulatory phase

Correct answer:

Ovulatory phase

Explanation:

The menstrual cycle has four phases: 

1) Menstrual phase (days 1-5): the uterus sheds its lining, which exits the body through the vagina in the form of menstrual fluid.

2) Follicular phase (days 1-13): the pituitary gland releases a hormone that stimulates the egg cells to grow. One egg cell matures in a sac-like follicle for 13 days; while it is maturing, the follicle releases a hormone that causes the uterus to develop its lining.

3) Ovulatory phase (day 14): the events listed in the question occur.

4) Luteal phase (days 15-28): the egg released during ovulation stays in the fallopian tube for 24 hours, disintegrating if not fertilized during that time. During this phase, the hormone that causes the uterus to retain its lining is used up, causing another menstrual phase to begin.

Learning Tools by Varsity Tutors