Question 1

How do the testes respond to exposure to excessive body warmth?

Accepted Answer

The testes respond to exposure to excessive body warmth by moving away from the pelvic cavity. This is because the scrotum, which houses the testes, is designed to regulate the temperature of the testes for proper sperm development. When the body is exposed to excessive warmth, the muscles of the scrotum contract and cause the testes to move away from the heat source in order to maintain their optimal temperature for sperm production.

Question 2

The ability of sperm cells to move along the ductus deferens is due to ________.

Accepted Answer

Sperm cells are moved through the ductus deferens (also known as vas deferens) by peristaltic contractions of smooth muscles in the duct. This muscular movement helps to propel the sperm towards the urethra. Enzymatic activity, hormonal action, and gravity do not have a significant role in the movement of sperm through the ductus deferens.

Question 3

Human egg and sperm are similar in that ________.

Accepted Answer

Human egg and sperm are similar in that they both contain half the number of chromosomes of normal body cells, which is 23 chromosomes each. This ensures that when they combine during fertilization, the resulting zygote has the full complement of 46 chromosomes.

Question 4

The oral contraceptive pill,informally called "the pill" contains an estrogen and progesterone or a synthetic mimic of this hormone.The combination of these two hormones taken in the pill and circulating in the blood work because.

Accepted Answer

The hormones in the pill mimic pregnancy, disrupting the ovarian cycle and preventing ovulation.

Question 5

The genetic determinate for male reproductive development is ________.

Accepted Answer

The SRY (sex-determining region on the Y chromosome) gene is responsible for male reproductive development. It triggers the development of testes and subsequent production of testosterone, which promotes further male development.

Question 6

All but one of the events described below occur during spermiogenesis.Select the event that does not occur during spermiogenesis.

Accepted Answer

Mitochondrial DNA is not packaged into the nucleus during spermiogenesis. Instead, the mitochondria form around the proximal end of the flagellum to provide ATP for the motility of the mature sperm.

Question 7

If gametes were diploid like somatic cells,how many chromosomes would the zygote contain?

Accepted Answer

If gametes were diploid like somatic cells, the resulting zygote would have twice the diploid number of chromosomes, disrupting normal development. This is because each succeeding generation would continue to double the chromosome number, resulting in an unmanageable number of chromosomes.

Question 8

Which of the following glands are responsible for 70% of the synthesis of semen?

Accepted Answer

The seminal vesicles are responsible for producing and secreting about 70% of the components of semen, including fructose, amino acids, and prostaglandins. The prostate gland also contributes to semen production, secreting enzymes and alkaline fluids that help to protect and nourish sperm. The bulbourethral glands secrete a small amount of pre-ejaculatory fluid, while the pituitary gland is involved in regulating hormone production related to sperm production and maturation.

Question 9

During spermiogenesis ________.

Accepted Answer

During spermiogenesis, the acrosome migrates towards the anterior end of the spermatid because its hydrolytic enzymes will be needed for penetration when the sperm contacts the egg during fertilization. The acrosome contains enzymes that help the sperm penetrate the zona pellucida, a protective layer surrounding the egg, allowing fertilization to occur.

Question 10

The dartos and cremaster muscles are important to the integrity of the male reproductive system.Which of the following is true about the role they play?

Accepted Answer

The dartos and cremaster muscles are responsible for regulating the temperature of the testes by contracting or relaxing to bring the testes closer or further away from the body. This helps to maintain the required temperature for sperm production in the testes.

Question 11

The structures that receive the ovulated oocyte,providing a site for fertilization,are called the ________.

Accepted Answer

The fallopian tubes receive the ovulated oocyte and provide a site for fertilization to occur.

Question 12

All but one of the following statements are true regarding the differences between early and late spermatids.Select the answer below that does not reflect a difference between early and late spermatids.

Accepted Answer

Early spermatids have already completed meiosis and are haploid, not diploid. This is the key difference between spermatids and their precursor cells, spermatocytes, which do undergo meiosis to reduce their chromosome number by half.

Question 13

All but one of the following statements describes the necessity of the blood testis barrier.Select the one statement that does not describe a necessity of the blood testis barrier.

Accepted Answer

The blood-testis barrier is essential for protecting developing sperm from the immune system, not for temperature regulation. Choices A, B, and D all relate to protecting sperm from being attacked by the immune system, which could recognize the unique antigens on sperm as foreign. Choice C, regarding temperature regulation, does not describe a necessity of the blood-testis barrier.

Question 14

Effects of estrogen include ________.

Accepted Answer

Estrogen is a hormone that promotes the growth and development of the female reproductive system. One of the effects of estrogen is the growth of the breasts at puberty.

Question 15

All but one of the following statements is true of uterine function.Select the statement that is not true of uterine function.

Accepted Answer

The most typical site of fertilization is the fallopian tubes, not the narrow portion of the uterus near the cervix.

Question 16

Which of the following hormones controls the release of anterior pituitary gonadotropins?

Accepted Answer

GnRH (gonadotropin-releasing hormone) is the hormone produced by the hypothalamus that regulates the release of gonadotropins (LH and FSH) from the anterior pituitary gland. Therefore, GnRH controls the release of anterior pituitary gonadotropins. Testosterone is a male hormone produced by the testes and does not directly control the release of gonadotropins. LH (luteinizing hormone) and FSH (follicle-stimulating hormone) are both gonadotropins released by the anterior pituitary gland and are not involved in regulating their own release.

Question 17

The most important risk for testicular cancer in young males is ________.

Accepted Answer

Testicular cancer is most commonly seen in young males, and failure of the testis to make their normal decent from the abdomen into the scrotum during fetal development is the most important risk factor for testicular cancer. This condition is known as cryptorchidism. Other risk factors include a family history of testicular cancer, certain genetic disorders, and previous testicular cancer. Sexually transmitted infections, a diet high in fat, and smoking are not considered significant risk factors for testicular cancer.

Question 18

Fertilization generally occurs in the ________.

Accepted Answer

Fertilization occurs in the fallopian tubes where the sperm meets the egg. It does not occur in the uterus, vagina, or ovary.

Question 19

In humans,separation of the cells at the two-cell state following fertilization may lead to the production of twins,which in this case would be ________.

Accepted Answer

The separation of cells at the two-cell stage following fertilization leads to the production of identical twins. These twins are genetically identical because they originated from the same fertilized egg. Thus, choice A is the best option. Fraternal twins, on the other hand, come from two separate eggs fertilized by different sperm cells, thus they are genetically different. Dizygotic twins are also fraternal twins, but they are formed when two separate ova are fertilized by two different sperm cells. They may or may not be of the same sex. Therefore, choices B, C, and D are not the best options in this case.

Question 20

All but one of the following statements is true with regard to the blood testis barrier.Select the one statement that is false.

Accepted Answer

The blood testis barrier is not made up of astrocytes. Instead, it is formed by tight junctions between the sustentocytes in the seminiferous tubules. Astrocytes are a type of glial cell found in the brain and spinal cord, not in the testes.

Quiz 27: The Reproductive System