Biology 30: Male & Female Reproductive Anatomy / Gametogenesis

What is the function of the testes?

Produce sperm and testosterone.

What is the function of the scrotum?

Holds the testes outside the body.

Where does spermatogenesis occur?

In the seminiferous tubules of the testes.

What is the function of the epididymis?

Stores sperm while they mature.

What is the function of the vas deferens?

Transports sperm toward the ejaculatory duct.

What is the function of the seminal vesicles?

Secrete fructose-rich fluid that provides energy for sperm.

What is the function of the prostate gland?

Secretes an alkaline fluid that protects sperm against vaginal acidity.

What is the function of Cowper's glands?

Release mucus before ejaculation to help clear the urethra of acidic urine.

What is the function of the ejaculatory duct?

Propels semen into the urethra.

What is the function of the urethra in males?

Transports semen out of the body during ejaculation.

What is the function of the penis?

Deposits sperm into the vagina.

What is semen made of?

Sperm mixed with fluids from the seminal vesicles, prostate gland, and Cowper's glands.

What is a vasectomy?

A procedure in which the vas deferens is cut or blocked to prevent sperm from entering semen.

What does the acrosome contain?

Acrosin, an enzyme that helps sperm penetrate the outer layer of the egg.

What is the function of testosterone?

Supports male reproductive development and sperm production.

Where is testosterone released?

By interstitial (Leydig) cells in the testes.

What is the function of luteinizing hormone (LH) in males?

Stimulates interstitial cells in the testes to produce testosterone.

What is the function of follicle-stimulating hormone (FSH) in males?

Stimulates Sertoli cells to support sperm production.

What is the function of gonadotropin-releasing hormone (GnRH)?

Stimulates the pituitary gland to release LH and FSH.

What is the correct sperm pathway from the testes to the vagina?

Seminiferous tubules → epididymis → vas deferens → ejaculatory duct → urethra → penis → vagina.

What is the function of the ovaries?

Contain follicles, release eggs, and secrete reproductive hormones.

What is the function of the fallopian tubes?

Carry the egg toward the uterus and provide the usual site of fertilization.

What is the function of the uterus?

A muscular organ where a fertilized egg can implant and develop.

What is the function of the endometrium?

The inner lining of the uterus where implantation can occur.

What is the function of the cervix?

Connects the uterus to the vagina.

What is the function of the vagina?

A muscular canal connecting the cervix to the outside of the body.

What is ovulation?

The release of an egg, or secondary oocyte, from a mature follicle in the ovary.

Where does ovulation occur?

In the ovary.

What is the corpus luteum?

The structure formed from the follicle after ovulation that secretes progesterone.

What is released during menstruation?

Blood and tissue from the shed uterine lining.

When does menstruation occur?

When pregnancy does not occur and the uterine lining is shed.

Where does fertilization usually occur?

In the fallopian tube.

What is a diploid cell?

A cell containing two sets of chromosomes (2n).

What is a haploid cell?

A cell containing one set of chromosomes (n).

What does polyploid mean?

Having more than two sets of chromosomes.

How many chromosomes are in a human diploid cell?

46 chromosomes (2n = 46).

How many chromosomes are in a human haploid cell?

23 chromosomes (n = 23).

If 4n = 44, what is n?

n = 44 ÷ 4 = 11.

If 4n = 44, what is 2n?

2n = 22.

If 4n = 44, what is 3n?

3n = 33.

What are homologous chromosomes?

Chromosomes that have the same genes in the same order but may carry different alleles.

What is a tetrad?

A pair of homologous chromosomes containing four chromatids.

What is synapsis?

The pairing of homologous chromosomes during prophase I.

What is crossing over?

The exchange of genetic material between homologous chromosomes during prophase I.

Why is crossing over important?

It increases genetic variation in the resulting cells.

What is the purpose of meiosis?

To reduce the chromosome number by half and produce genetically unique haploid cells.

What happens during interphase before meiosis?

DNA replicates, so each chromosome consists of two sister chromatids.

What happens during early prophase I?

Chromosomes condense, the nuclear membrane dissolves, spindle fibers form, and homologous chromosomes pair.

What happens during late prophase I?

Homologous chromosomes undergo crossing over.

What happens during metaphase I?

Tetrads line up at the middle of the cell.

What happens during anaphase I?

Homologous chromosomes separate and move to opposite poles.

What happens during telophase I?

Chromosomes reach opposite poles, and nuclear membranes may form.

What happens during cytokinesis I?

The cell divides into two haploid cells whose chromosomes still have two sister chromatids.

What happens during prophase II?

Chromosomes condense, and spindle fibers form in each cell.

What happens during metaphase II?

Chromosomes line up individually at the middle of each cell.

What happens during anaphase II?

Sister chromatids separate and move to opposite poles.

What happens during telophase II?

Nuclear membranes form, and chromosomes begin to de-condense.

What happens during cytokinesis II?

The cells divide, producing four haploid daughter cells.

What happens to chromosome number during meiosis I?

It is reduced by half as homologous chromosomes separate.

What happens to sister chromatids during meiosis II?

They separate, leaving each chromosome with one chromatid.

Why are the cells produced by meiosis genetically unique?

Crossing over and independent assortment create genetic variation.

Why are females born with a finite number of eggs?

They are born with a limited supply of immature eggs in ovarian follicles.

Why is oogenesis discontinuous?

Egg development occurs in stages over reproductive cycles rather than continuously.

What happens when ovarian follicles are depleted?

Menopause occurs.

What is the sequence of spermatogenesis?

Spermatogonium → primary spermatocyte → secondary spermatocytes → spermatids → mature sperm.

What is the result of one primary spermatocyte?

Four haploid sperm cells.

When does spermatogenesis occur?

It begins at puberty and continues through most of a male's life.

What is the result of oogenesis?

One functional egg and three polar bodies.

Why does oogenesis produce only one functional egg?

The cytoplasm divides unequally, allowing one egg to receive most of the cytoplasm.

What happens to polar bodies?

They do not develop into functional eggs and cannot be fertilized.

Why is spermatogenesis more productive than oogenesis?

One primary spermatocyte produces four functional sperm, while one primary oocyte produces one functional egg.