Question 1

Which of the following are examples of sexually dimorphic behaviors in rats?
A) eating
B) parenting
C) mating
D) sleeping
E) all locomotion

Accepted Answer

Mating behavior is sexually dimorphic in rats, with males exhibiting more aggressive and active behavior while females exhibit more passive and receptive behavior.

Question 2

The adulthood psychological adjustment achieved by Bruce-Brenda-David, the male twin whose penis was ablated during a botched circumcision procedure at age 7 months, suggests that
A) nature's impulse is to create a female.
B) sexual identity may not be easily shifted by the upbringing of a child.
C) regular injections of testosterone can shift sexual identity.
D) genetic type is less important than are social factors.
E) normal circumcision can alter sexual identity.

Accepted Answer

The fact that Bruce-Brenda-David's psychological adjustment as an adult suggests that sexual identity may not be easily shifted by upbringing indicates that this individual's gender identity was not solely determined by social factors. This supports choice B over the other options.

Question 3

Which of the following is true of the sex chromosomes?
A) Factors coded on the Y chromosome control the development of the male sex glands.
B) The Y chromosome contains the blueprints for the male fetus.
C) The sex chromosomes are the largest among the 23 pairs.
D) The mother donates her Y chromosome to form a female fetus.
E) The Y chromosome contains the blueprints for the female fetus.

Accepted Answer

Factors coded on the Y chromosome, specifically the SRY gene, control the development of the male sex glands.

Question 4

Gametes are unique reproductive cells that
A) secrete Müllerian-inhibiting substance.
B) contain 23 pairs of chromosomes.
C) carry half the genetic information of other cells of the body.
D) are formed by the union of an egg and a sperm during fertilization.
E) will eventually form the sex organs of the fetus.

Accepted Answer

Gametes carry only one set of chromosomes or half the genetic information of other cells in the body. This is essential for the production of offspring with genetic diversity. Options A, B, D, and E do not accurately describe gametes.

Question 5

The prenatal development of the internal reproductive structures of the female
A) requires the suppression of the Müllerian system by anti-Müllerian hormone.
B) requires secretion of estradiol by the pituitary.
C) is caused by secretion of progesterone.
D) requires no hormone.
E) requires secretion of androgens.

Accepted Answer

The prenatal development of the internal reproductive structures of the female requires no hormone. In females, the Müllerian system develops into the fallopian tubes, uterus, and the inner part of the vagina naturally in the absence of anti-Müllerian hormone, which is secreted in males to suppress the Müllerian system.

Question 6

The structures of the Wolffian system are the precursors to the
A) male internal sex organs.
B) ovaries.
C) female internal sex organs.
D) testes.
E) penis and scrotum.

Accepted Answer

The Wolffian system develops into the male internal sex organs, including the epididymis, vas deferens, and seminal vesicles. The female internal sex organs arise from the Müllerian system. The ovaries develop separately from both systems. The penis and scrotum form from external genitalia structures.

Question 7

The prenatal development of the internal reproductive structures of the male requires
A) activation of the Müllerian system by anti-Müllerian hormone.
B) secretion of estradiol by the pituitary.
C) secretion of progesterone.
D) secretion of androgens.
E) secretion of progresterone.

Accepted Answer

The prenatal development of the internal reproductive structures of the male requires secretion of androgens, such as testosterone, which stimulate the development of the Wolffian ducts and the differentiation of the epididymis, vas deferens, and seminal vesicles.

Question 8

The key factor that determines whether the undifferentiated gonads develop into testes is the
A) gene Sry located on the Y chromosome.
B) secretion of testosterone from the adrenals.
C) gene Sry located on the X chromosome.
D) 21st pair of chromosomes.
E) secretion of androgens from the gonads.

Accepted Answer

The gene Sry located on the Y chromosome is responsible for the development of testes. Its absence in individuals with XX chromosomes results in the development of ovaries.

Question 9

A hormone that prevents the prenatal development of the Müllerian system is said to have a(n)
A) defeminizing effect.
B) activational effect.
C) masculinizing effect.
D) feminizing effect.
E) nonselective action on the undifferentiated gonads.

Accepted Answer

A hormone that prevents the prenatal development of the Müllerian system is said to have a defeminizing effect, as it prevents the development of female reproductive structures.

Question 10

An example of a sexually dimorphic behavior noted in humans would be
A) breathing.
B) eating.
C) breastfeeding.
D) grooming of hair.
E) vigorous exercise.

Accepted Answer

Breastfeeding is a sexually dimorphic behavior because it is a behavior that is typically performed by females due to biological differences, specifically the presence of mammary glands.

Question 11

A hormone that promotes the prenatal development of the Wolffian system is said to have a(n)
A) defeminizing effect.
B) activational effect.
C) masculinizing effect.
D) feminizing effect.
E) nonselective action on the undifferentiated gonads.

Accepted Answer

The prenatal development of the Wolffian system is a masculinizing effect, as this system develops into male reproductive organs (epididymis, vas deferens, seminal vesicles). Hormones that promote this development, such as testosterone, have a masculinizing effect.

Question 12

An example of an activational effect induced by the hormone estradiol would be
A) growth of the uterine lining during the menstrual cycle.
B) growth of axillary hair in females.
C) differentiation of the Wolffian system into the fimbriae, Fallopian tubes, uterus, and vagina.
D) maturation of the ovaries in a female.
E) alteration of the vocal cords to create a "deep" voice.

Accepted Answer

Estradiol is responsible for the growth and thickening of the uterine lining during the menstrual cycle, which is an activational effect. The other options either refer to developmental effects or effects not mediated by estradiol.

Question 13

Which of the following terms belong together?
A) Wolffian system; clitoris
B) Müllerian system; Fallopian tubes
C) Müllerian system; uterus
D) Wolffian system; uterus
E) Müllerian system; vas deferens

Accepted Answer

The answer of Which of the following terms belong together?
A)...

Question 14

The genetic sex of a fetus is determined by
A) the hormones produced by the pituitary during fetal development.
B) a single gene on the X chromosome.
C) the gonads.
D) the father's sperm.
E) the phase of the menstrual cycle during which fertilization occurs.

Accepted Answer

The genetic sex of a fetus is determined by the father's sperm, as it can carry either an X or a Y chromosome, while the mother's egg only carries an X chromosome. The combination of these chromosomes (XX for female, XY for male) determines the genetic sex of the fetus.

Question 15

Which of the following is considered to be a human sex organ?
A) ovaries
B) adrenal gland
C) pancreas
D) pituitary
E) thyroid

Accepted Answer

The ovaries are considered to be a human sex organ as they are responsible for producing and releasing eggs as well as secreting hormones such as estrogen and progesterone which are involved in reproductive processes. The adrenal gland, pancreas, pituitary, and thyroid are all important endocrine glands but are not considered to be sex organs.

Question 16

The Müllerian system structures are the precursors to the
A) male internal sex organs.
B) ovaries.
C) female internal sex organs.
D) testes.
E) penis and scrotum.

Accepted Answer

The Müllerian system structures develop into the female internal sex organs, such as the uterus, fallopian tubes, and upper portion of the vagina. They are not involved in the development of male internal sex organs (option A), ovaries (option B), testes (option D), or external male genitalia (option E).

Question 17

The key distinction between an organizational hormone effect and an activational hormone effect is that
A) activational effects are permanent.
B) organizational effects are permanent.
C) organizational effects only occur during adulthood.
D) activational effects are mediated by receptors, whereas organizational effects are due to temporary changes in neurotransmitter secretion.
E) organizational effects only occur in the brain.

Accepted Answer

Organizational effects are permanent changes in the brain or body due to exposure to hormones during specific developmental periods, such as puberty. Activational effects, on the other hand, are temporary changes in behavior or physiology due to hormone secretion in response to a specific stimulus, such as stress or mating.

Question 18

The hormone ________ exerts a defeminizing action during prenatal development.
A) testosterone
B) dihydrotestosterone
C) estradiol
D) ghrelin
E) anti-Müllerian hormone

Accepted Answer

The answer of The hormone ________ exerts a defeminizing action...

Question 19

The formation of the ovaries during prenatal development is controlled by
A) the Sry gene.
B) testosterone.
C) the X chromosome.
D) the Y chromosome.
E) no factor.

Accepted Answer

The answer of The formation of the ovaries during prenatal...

Question 20

The protein that dictates the conversion of the undifferentiated gonads into the testes is controlled by the
A) ob/ob protein.
B) leptin protein.
C) gene Tny.
D) gene Sry.
E) X chromosome.

Accepted Answer

The gene Sry, located on the Y chromosome, is responsible for the initiation of testis development in mammals.

Quiz 10: Reproductive Behavior

Which of the following are examples of sexually dimorphic behaviors in rats?

The adulthood psychological adjustment achieved by Bruce-Brenda-David, the male twin whose penis was ablated during a botched circumcision procedure at age 7 months, suggests that

Which of the following is true of the sex chromosomes?

Gametes are unique reproductive cells that

The prenatal development of the internal reproductive structures of the female

The structures of the Wolffian system are the precursors to the

The prenatal development of the internal reproductive structures of the male requires

The key factor that determines whether the undifferentiated gonads develop into testes is the

A hormone that prevents the prenatal development of the Müllerian system is said to have a(n)

An example of a sexually dimorphic behavior noted in humans would be

A hormone that promotes the prenatal development of the Wolffian system is said to have a(n)

An example of an activational effect induced by the hormone estradiol would be

Which of the following terms belong together?

The genetic sex of a fetus is determined by

Which of the following is considered to be a human sex organ?

The Müllerian system structures are the precursors to the

The key distinction between an organizational hormone effect and an activational hormone effect is that

The hormone ________ exerts a defeminizing action during prenatal development.

The formation of the ovaries during prenatal development is controlled by

The protein that dictates the conversion of the undifferentiated gonads into the testes is controlled by the