Female Gametogenesis

In which of the following female reproductive structures does oogenesis begin?

uterus

Fallopian tubes

vagina

ovaries

cervix

Which numbered structure below represents an ovary?

1

2

3

4

5

As is the case in spermatogenesis, oogenesis begins with diploid cells that multiply by mitosis. The diploid cells in oogenesis are called oogonia.

When does the process of oogenesis and the formation of oogonia begin in a female?

when the female enters puberty

when the female is still a fetus

shortly after the female is born

each month at the start of the female’s menstrual cycle

Meiosis begins in the ovaries while the female is still a fetus but stops at __________.

anaphase I

interphase

metaphase I

metaphase II

prophase I

prophase II

At this point, when the cell is arrested in prophase I of meiosis, what is it called?

primary oocyte

secondary oocyte

follicle cell

polar body

primary oogonium

The cell is now called a primary oocyte. It is contained within a structure known as the follicle inside of the ovary. The cells that comprise the follicle will support and nurture the developing egg.

during the last trimester of fetal development

shortly after the female is born

when the female reaches puberty

when the female ovulates

when the primary oocyte is fertilized by a sperm

When meiosis resumes, the primary oocyte divides to form a large _______ and a smaller _______.

primary oocyte; secondary oocyte

secondary oocyte; follicle cell

primary oocyte; follicle cell

secondary oocyte; polar body

ovum; polar body

True or False:

After the primary oocyte divides to form the secondary oocyte and polar body during meiosis I, the process arrests again.

True

False

The next step in female gametogenesis is ovulation. What generally happens during ovulation?

A single follicle in one ovary ruptures, releasing the secondary oocyte into the uterus.

A single follicle in one ovary ruptures, releasing the secondary oocyte into the Fallopian tube.

One ovary releases the entire follicle (including the secondary oocyte and polar body) into the Fallopian tube.

One ovary releases the entire follicle (including the secondary oocyte and polar body) into the uterus.

Several follicles in both ovaries rupture and release many secondary oocytes into the Fallopian tubes.

During ovulation, generally a single follicle in one ovary ruptures, and the secondary oocyte and a few follicle cells are released into the Fallopian tube. Most of the follicle cells, however, remain in the ovary and form a transient endocrine structure called the corpus luteum.

1

2

3

4

5

In which of the following structures is fertilization most likely to occur?

1

2

3

4

5

At what point does the process of meiosis resume?

during the process of ovulation

after fertilization by a sperm

when the female reaches puberty

when the female reaches menopause

After fertilization, the secondary oocyte completes meiosis to form a large ________ and a smaller ________.

secondary oocyte; ovum (egg)

ovum (egg); polar body

ovum (egg); follicle cell

polar body; ovum (egg)

ovum (egg); secondary oocyte

Why does oogenesis involve two asymmetrical divisions that ultimately result in a large ovum that receives most of the cytoplasm and smaller polar bodies that receive almost no cytoplasm?

Eggs need to be large so that the sperm can locate them more easily.

The polar bodies are needed to generate the hormones needed for the maintenance of pregnancy.

Eggs and polar bodies can both be fertilized by sperm to produce multiple babies.

The egg needs a large supply of materials within the cytoplasm to support early development.

All of the above.

The fertilized egg (zygote) now travels towards the uterus for implantation. Which numbered structure below represents the uterus?

1

2

3

4

5

Hormones regulate the timing of both the ovarian and menstrual cycles. It is essential that these two cycles be linked so that the uterus is prepared to receive and nurture the embryo if fertilization does occur. Which of the following events marks the first day of the menstrual cycle?

ovulation

the first day of bleeding associated with the shedding of the endometrium

the last day of bleeding associated with the shedding of the endometrium

formation of the corpus luteum

when a follicle grows to maturity

When circulating estrogen levels are low, the anterior pituitary gland produces increasing amounts of which of the following hormones?

progesterone

estrogen

testosterone

human chorionic gonadotropin (hCG)

follicle-stimulating hormone (FSH)

What is the effect of increasing levels of follicle-stimulating hormone (FSH)?

It stimulates thickening of the endometrium.

It stimulates a few follicles in the
ovaries to grow and develop.

It stimulates ovulation.

It stimulates formation of the corpus luteum.

It triggers the shedding of the endometrium.

Which hormone is produced and released by the developing follicles?

follicle-stimulating hormone (FSH)

luteinizing hormone (LH)

estrogen

human chorionic gonadotropin (hCG)

testosterone

High levels of estrogen trigger the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. What is the effect of the LH surge?

It stimulates thickening of the endometrium.

It stimulates a few follicles in the
ovaries to grow and develop.

It stimulates ovulation.

It stimulates formation of the corpus luteum.

It triggers the shedding of the endometrium.

After ovulation, the follicle cells remaining in the ovary form the corpus luteum. Which hormone(s) are produced by the corpus luteum?

follicle-stimulating hormone (FSH)

luteinizing hormone (LH)

estrogen

progesterone

progesterone and estrogen

FSH and LH