Chap 10

Question 1

In males, the SRY gene causes the development of testes and in females, the SRY gene causes the development of ovaries.

Answer 1

False

Question 2

The activating effects of hormones produce enduring structural effects.

Answer 2

False

Question 3

The human sensitive period for genital formation occurs during the second trimester of pregnancy.

Answer 3

False

Question 4

Levels of testosterone correlate positively with men’s drive to seek sexual partners.

Answer 4

True

Question 5

Late in pregnancy, the areas of the female rat brain involved in maternal behavior become more sensitive to estradiol.

Answer 5

True

Question 6

An evolutionary explanation of mate preferences suggests that women prefer good providers because they need help during pregnancy and when caring for small children.

Answer 6

True

Question 7

A genetic male with congenital adrenal hyperplasia will have genitals resembling those of a female.

Answer 7

False

Question 8

Twin studies indicate that there is concordance for homosexual activity, but the magnitude of the effect has varied considerably across studies.

Answer 8

True

Question 9

At an early stage of embryological development, before the influence of sex hormones, what is the appearance of a fetus’s external genitals?

Answer 9

Both sexes have small “unisex” structures that could develop into either a penis or a clitoris.

Question 10

Sex hormones affect neurons in several ways. Which of the following is not one of those ways?

Answer 10

Brain enzymes convert them into dopamine and other neurotransmitters.

Question 11

What is the main difference between organizing effects and activating effects of hormones?

Answer 11

Organizing effects are long lasting, whereas activating effects are temporary.

Question 12

If a developing mammal is exposed to high levels of both androgens and estrogens, its external anatomy will appear ________ . If it is exposed to low levels of both, its external anatomy will appear ________ .

Answer 12

masculine . . . feminine

Question 13

How does sexual differentiation of the brain differ between rodents and primates?

Answer 13

In rodents, testosterone must be aromatized to estradiol before it affects developing neurons

Question 14

How much a child plays with boys’ toys is apparently increased by prenatal exposure to ________ and decreased by prenatal exposure to ________ .

Answer 14

testosterone… phthalates

Question 15

In terms of neurotransmitter activity, how does the mechanism of erection differ from that of orgasm?

Answer 15

Erection depends on one set of dopamine receptors and orgasm depends on different dopamine receptors.

Question 16

Compared to other men, what are the testosterone levels of married men?

Answer 16

Lower than average

Question 17

At what time, if any, during the menstrual cycle do women’s sexual desires tend to be highest, in women not taking birth-control pills?

Answer 17

Sexual desire is highest during the periovulatory period.

Question 18

What effect, if any, do sex hormones have on people’s ability to recognize facial expressions of emotion?

Answer 18

Testosterone impairs the ability to recognize emotional expressions.

Question 19

What hormonal levels, if any, correlate with the amount of time and care that human fathers give their young children?

Answer 19

High levels of prolactin and low levels of testosterone

Question 20

What is meant by “sexual selection”?

Answer 20

Evolution favors characteristics that make an individual more appealing to the opposite sex.

Question 21

In a fetus with congenital adrenal hypertrophy (CAH), the adrenal gland produces ________ cortisol, and as a result, the pituitary directs the adrenal gland to produce ________ testosterone.

Answer 21

less than average . . . more than average

Question 22

A girl’s interest in boys’ toys correlates positively with which of the following?

Answer 22

Exposure to testosterone before birth

Question 23

What condition occurs if a male lacks the receptor that enables androgens to activate genes in a cell’s nucleus?

Answer 23

Testicular feminization

Question 24

When genetic males lacked the enzyme that converts testosterone to dihydroxytestosterone, what happened to their sexual development?

Answer 24

They looked female at birth but developed male structures at puberty

Question 25

On average, how do heterosexual and homosexual men compare in height?

Answer 25

On average, heterosexual men are only very slightly taller.

Question 26

Of the following, which is the LEAST plausible hypothesis for why natural selection has not eliminated genes for male homosexuality?

Answer 26

Some homosexual men have children.

Maybe there is no gene for homosexuality. Instead, an environmental event produces an epigenetic effect that can be transmitted from one generation to the next.

Homosexual people might spread their genes by helping their brothers and sisters rear their children.

Perhaps the relatives of a homosexual male have more than an average number of children.

Question 27

Which of the following would increase the probability that a boy will develop a homosexual orientation?

Answer 27

Having a biological older brother, even if he did not live in the same house

Question 28

How might stress to a pregnant rat alter the sexual orientation of her male offspring?

Answer 28

Stress increases the release of endorphins in the hypothalamus.

Question 29

In what way was INAH-3 distinctive for most of the homosexual men in LeVay’s study and the follow-up research?

Answer 29

This nucleus had neurons with smaller than average volume.

Question 30

The ________ are present in both male and female embryos, and are the precursors for the male internal reproductive structures.

Answer 30

Wolffian ducts

Question 31

Which gene signals undeveloped fetal gonads to become testes?

Answer 31

SRY

Question 32

In humans, the prominent estrogen is ________ .

Answer 32

estradiol

Question 33

In humans, the sensitive period for determining whether a fetus will become male or female is during the ________ .

Answer 33

first trimester only

Question 34

Which term describes hormonal effects that produce long-lasting structural changes?

Answer 34

organizing

Question 35

Research with rodents has shown that ________ .

Answer 35

injecting a genetic male with estrogens produces little effect on his external anatomy

Question 36

Researchers found that the sons of women with high urinary ________ levels during pregnancy show less interest in typically “male” toys and more interest in typically “female” toys than do sons of women with lower levels.

Answer 36

phthalate

Question 37

People typically experience a state of relaxation shortly after orgasm as a result of ________ release.

Answer 37

oxytocin

Question 38

Testosterone primes the MPOA and several other brain areas to release ________ , which facilitates erection of the penis in the male.

Answer 38

dopamine

Question 39

One consequence of high estradiol and progesterone levels during pregnancy is fluctuating activity at the ________ receptor, which is responsible for nausea.

Answer 39

serotonin 3

Question 40

Women not taking birth-control pills initiate sexual activity more often during the ________ phase than at any other time of their cycles.

Answer 40

periovulatory

Question 41

On average, a man’s ________ level decreases while his ________ level increases after a baby is born, especially if he spends hours a day interacting with the child.

Answer 41

testosterone; prolactin

Question 42

In rodents, which substance secreted by the posterior pituitary gland is important for social behavior in many species, partly by facilitating olfactory recognition of other individuals?

Answer 42

vasopressin

Question 43

In countries where women have good educational, economic, and employment opportunities, a woman is more likely to choose a partner close to her own age, indicating a(n) ________ component to mate choice in humans.

Answer 43

learned

Question 44

The differences that result from an individual’s self-identification as either male or female are properly known as ________ differences.

Answer 44

gender

Question 45

Individuals born with intermediate sexual development are considered to be ________ .

Answer 45

intersex

Question 46

Current recommendations for rearing an intersex child include ________ .

Answer 46

identifying the child as male or female based on the predominant external appearance

Question 47

With respect to sexual orientation, ________ .

Answer 47

women are slower to discover their orientation than are men

Question 48

Studies of the genetics of sexual orientation have found that ________ .

Answer 48

it is unlikely that a gene on the X chromosome plays a major role in homosexuality

Question 49

Studies of brain anatomy have shown that, on average, ________ .

Answer 49

lesbian women’s brains are slightly shifted in the male direction in some ways but not others