MCAT Biology : Other Reproductive Physiology

Study concepts, example questions & explanations for MCAT Biology

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Example Questions

Example Question #21 : Systems Biology And Tissue Types

Which of the following is an alternative to sexual reproduction?

Possible Answers:

Parthenogenesis

Hermaphroditism

Pseudohermaphroditism

Isogamy

Correct answer:

Parthenogenesis

Explanation:

Parthenogenesis is the activation and development of an egg without sperm. Parthenogensis, therefore, is not sexual reproduction, but can still result in a fully developed offspring.

Isogamy is a condition of indistinguishable male and female gametes, but they retain the ability to join in sexual reproduction. Hermaphroditism and pseudohermaphroditism are rare conditions in which a single organism produces both sperm and eggs and is able to self-fertilize in sexual reproduction.

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:

Ovulatory phase

Vaginal phase

Menstrual phase

Follicular phase

Luteal 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.

Example Question #23 : Systems Biology And Tissue Types

Which of the following is incorrect regarding female/male differences?

Possible Answers:

Males only produce testosterone, but females produce estrogen both estrogen and testosterone

Females produce estrogen in higher amounts than testosterone

Both males and females produce testosterone and estrogen

Both males and females produce progesterone

Males produce testosterone in higher amounts than estrogen

Correct answer:

Males only produce testosterone, but females produce estrogen both estrogen and testosterone

Explanation:

Hormone balance is extremely important in both developing the male and female fetus. Hormone levels can regulate and determine the relative level of sex characteristics that we see in individuals. Both sexes produces testosterone and estrogen, but utilize the hormones in different ways. Testosterone is produced at higher levels in males and is used to develop male secondary sex characteristics. Estrogen is produced at higher levels in females and is used to develop female secondary sex characteristics.

Progesterone is a secondary sex hormone that is also produced in both sexes. Females use progesterone to regulate the menstrual cycle, and levels of the hormone vary in women.

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