Deck 11: Reproductive Behaviors

Question 1

Nature's "default setting" is to make every mammal a female in its external anatomy.

Answer 1

True

Question 2

Estradiol does not contribute to female development.

Answer 2

False

Question 3

Stimulation of the medial preoptic area increases sexual activity in rodents.

Answer 3

True

Question 4

Organizing effects of hormones usually occur early in development.

Question 5

Drugs that reduce testosterone levels in males will most likely reduce their sexual behavior.

Question 6

Hormones produced by the ovaries are required for proper maternal behavior in rats.

Question 7

In general, men are more jealous of sexual infidelity than women.

Question 8

Birth-control pills prevent pregnancy by interfering with the usual feedback cycle between the ovaries and the pituitary.

Question 9

During the early sensitive period, immature mammals have a protein called alpha-fetoprotein, which is also present in adults.

Question 10

Estrogen production by the ovary causes the male Wolffian system to degenerate in females.

Question 11

The sex hormones include the estrogens, progesterone, and the androgens.

Question 12

Estrogens are present only in females.

Question 13

The sexually dimorphic nucleus is larger in females than males.

Question 14

The changes in estrogen levels just before menstruation are the cause of PMS.

Question 15

Progesterone prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy.

Question 16

Testosterone levels continue to increase throughout a human male's lifetime.

Question 17

High levels of estrogen and progesterone will prevent ovulation.

Question 18

Activating effects can occur at any time in life when a hormone temporarily activates a particular response.

Question 19

Hormones are capable of inducing long-lasting changes throughout the body.

Question 20

In humans, testosterone produces its organizing effects on the hypothalamus by itself.

Question 21

All of the following hormones affect the brain and the genitals EXCEPT:

A) testosterone.
B) androgen.
C) aromatase.
D) estradiol.

Question 22

Some differences in males and females depend directly on control by the ____ independently of hormones.

A) X chromosome
B) Y chromosome
C) X and Y chromosomes
D) hormones

Question 23

"Female hormones" are referred to as:

A) activating hormones.
B) SRY.
C) androgens.
D) estrogens.

Question 24

Which is true of androgens and estrogens?

A) Only males have androgens; only females have estrogens.
B) Only males have estrogens; only females have androgens.
C) Males and females have androgens and estrogens in similar amounts.
D) Males and females both have androgens and estrogens, but in different amounts.

Question 25

Which hormone(s) is/are likely to be found more abundantly in males than in females?

A) Peptide hormones
B) Androgens
C) Progesterone
D) Estrogens

Question 26

Genes on the ____ produce(s) sex differences in addition to those that we can trace to androgens and estrogens.

A) Y chromosome
B) X chromosome
C) hormones
D) X and Y chromosomes

Question 27

The difference in the size of the INAH3 in homosexual and heterosexual men is mainly because of a difference in the number of neurons.

Question 28

Which of the following is true of androgens and estrogens?

A) Only males have androgens.
B) Both sexes have both types of hormones.
C) They are produced by the pituitary.
D) They have opposite effects in males and females.

Question 29

Steroid hormones produce their effects by:

A) disrupting cell membranes.
B) opening ion channels.
C) increasing cholesterol levels.
D) entering cells and affecting gene expression.

Question 30

Which hormone(s) is/are likely to be found more abundantly in females than in males?

A) Peptide hormones
B) Androgens
C) Progesterone
D) Estrogens

Question 31

Girls with CAH are more likely to participate in "tomboyish" activities.

Question 32

There are obvious differences in external anatomy of homosexual humans compared to heterosexual humans.

Question 33

Two major classes of sex hormones are:

A) luteinizing hormone and follicle-stimulating hormone.
B) dopamine and serotonin.
C) steroids and thyroid hormones.
D) androgens and estrogens.

Question 34

Androgen insensitivity syndrome leads to a genetic male with a female external appearance of the genitals.

Question 35

____ prepares the uterus for pregnancy.

A) Testosterone
B) Androgen
C) Progesterone
D) Estradiol

Question 36

Brains of male homosexuals are completely identical to brains of female heterosexuals.

Question 37

The hormone that prepares the uterus for pregnancy is:

A) testosterone.
B) androgen.
C) progesterone.
D) estradiol.

Question 38

"Male hormones" are referred to as:

A) activating hormones.
B) SRY.
C) androgens.
D) estrogens.

Question 39

When do the organizing effects of sex hormones occur in humans?

A) well before birth
B) shortly before and after birth
C) during childhood
D) during adolescence

Question 40

Although harmful in excessive amounts, the synthesis of steroids depends on:

A) heavy metals.
B) cholesterol.
C) ethanol.
D) insulin.

Question 41

Genitals for males and females develop from ____; internal reproductive structures develop from ____.

A) a single unisex structure; separate structures
B) separate structures; a single unisex structure
C) a single unisex structure; a single unisex structure
D) separate structures; separate structures

Question 42

Sexual differentiation begins with:

A) Wolffian ducts
B) chromosomes
C) Müllerian ducts
D) Hormones

Question 43

In general, when do hormones produce "organizing effects"?

A) whenever the levels of some other hormone have decreased
B) during early stages in development
C) during adulthood
D) temporarily at any time in life

Question 44

In comparison to activating effects, organizing effects of hormones take place:

A) later in life and produce more long-lasting effects.
B) later in life and produce more temporary effects.
C) earlier in life and produce more long-lasting effects.
D) earlier in life and produce more temporary effects.

Question 45

What causes the primitive gonads to develop into masculine structures?

A) the X chromosome
B) the sex region Y (SRY) gene
C) the sexually dimorphic nucleus
D) Müllerian inhibiting hormone

Question 46

The result of all the testosterone-induced changes during sexual differentiation is:

A) the bladder and urethra
B) peripheral nerves controlling the genitals
C) female reproductive structures
D) male reproductive structures

Question 47

One important difference between organizing effects and activating effects of hormones is that activating effects:

A) are shorter-term.
B) take place mostly during an early sensitive period.
C) cause the pituitary gland to release another hormone.
D) control only the peripheral nervous system.

Question 48

Which of the following depends on an organizing effect of hormones?

A) whether an organism develops as male or female
B) the degree of sexual activity at any time
C) the timing of migration or hibernation
D) current metabolic rate

Question 49

Müllerian ducts are found in:

A) genetic female fetuses only.
B) genetic male fetuses only.
C) female and male fetuses early in development.
D) female and male fetuses until shortly before birth.

Question 50

What determines whether a mammal develops male or female external genitals?

A) the amount of testosterone during prenatal development
B) the amount of estrogens during prenatal development
C) the difference (subtraction) between testosterone and estrogen levels in prenatal development
D) the ratio (division) between testosterone and estrogen levels in prenatal development

Question 51

An organizing effect differs from an activating effect of a hormone in that an organizing effect:

A) inhibits the effects of another hormone.
B) lasts only briefly.
C) activates excitatory receptors.
D) produces more long-lasting effects.

Question 52

When do the organizing effects of sex hormones occur in rats?

A) well before birth
B) shortly before and after birth
C) during their juvenile period
D) at approximately two months of age

Question 53

What develops from the Wolffian ducts?

A) the bladder and urethra
B) peripheral nerves controlling the genitals
C) female reproductive structures
D) male reproductive structures

Question 54

What develops from the Müllerian ducts?

A) the bladder and urethra
B) peripheral nerves controlling the genitals
C) female reproductive structures
D) male reproductive structures

Question 55

What would cause a genetic female mammal to develop an anatomical appearance resembling a male's?

A) a lack of estradiol
B) moderate levels of estradiol during an early stage of development
C) a high level of testosterone during an early stage of development
D) a high level of testosterone during the late part of puberty

Question 56

Which of the following is most likely an example of the organizing effects of sex hormones?

A) increased heart rate during exercise
B) determination of genetic sex
C) masculinization of the brain
D) nest building

Question 57

Wolffian ducts are found in:

A) genetic female fetuses only.
B) genetic male fetuses only.
C) female and male fetuses early in development.
D) female and male fetuses until shortly before birth.

Question 58

Why is it impossible for an individual to develop a complete, normal set of external female genitalia AND a complete, normal set of external male genitalia?

A) An individual has either estradiol or testosterone, but not both.
B) Both types of external genitalia develop from the same fetal structure.
C) Development of the external genitalia is not influenced by early hormonal levels.
D) The female genitals reach maturity earlier than the male genitals.

Question 59

How does the development of external genitalia differ from the development of the internal reproductive structures?

A) Reproductive structures are influenced by hormone levels; genitals are not.
B) Reproductive structures for males and females develop from a single unisex structure; genitals develop from separate Wolffian and Müllerian structures.
C) Genitals for males and females develop from a single unisex structure; reproductive structures develop from separate Wolffian and Müllerian structures.
D) Genital development is controlled by estrogen; the reproductive structures are controlled by androgen.

Question 60

Which of the following is unique to genetic males early in development?

A) Wolffian ducts
B) primitive gonads
C) Müllerian ducts
D) Müllerian inhibiting hormone

Question 61

If you expose a female to testosterone early in life, it will cause her hypothalamus to:

A) decrease in size.
B) develop a cyclic pattern of hormone release.
C) develop more like a typical male hypothalamus (noncyclic).
D) become inactive.

Question 62

Genetic males with testicular feminization (androgen insensitivity) develop looking and acting female. This condition develops because of a genetic mutation that has which effect?

A) It decreases the production of cortisol.
B) It prevents the production of testosterone.
C) It causes a conversion of testosterone into estradiol within certain cells.
D) It prevents testosterone from having its usual effects.

Question 63

____ contributes to female development, including some aspects of brain differentiation.

A) Testosterone
B) Estradiol
C) Androgen
D) Estrogen

Question 64

If you inject a male rat with estrogen shortly after birth, it will:

A) still develop into a male.
B) still develop into a male, but will act very much like a female.
C) develop into something intermediate between female and male.
D) develop into a female.

Question 65

Nature's "default setting" is to make every mammal's external anatomy:

A) male.
B) female.
C) intermediate between male and female.
D) fully both male and female.

Question 66

The sensitive period for human genital formation is approximately:

A) the first three weeks of gestation.
B) the third and fourth months of gestation.
C) the last trimester of gestation.
D) shortly after birth.

Question 67

During an early sensitive period, a mammal is exposed to high levels of both androgens (such as testosterone) and estrogens (such as estradiol). How will its external genital anatomy appear?

A) about like that of a normal male
B) intermediate between male and female
C) about like that of a normal female
D) either, depending on the presence or absence of a Y chromosome

Question 68

The overall mechanism of early sexual differentiation has been described by saying that nature's "default setting" is to make every mammal:

A) male.
B) female.
C) intermediate between male and female.
D) fully both male and female.

Question 69

A sensitive period is:

A) any time in an organism's life when it is sensitive to hormones released by the sexually dimorphic nucleus.
B) an early period when a hormone has a long lasting effect.
C) an early period when a hormone has an intense, but brief, effect.
D) a period of time, usually once a month, when hormones are released.

Question 70

What would cause a mammal to develop the anatomy of a male, regardless of its chromosomes?

A) exposure to high levels of testosterone during an early stage of development
B) deprivation of estradiol during an early stage of development
C) exposure to neither testosterone nor estradiol during an early stage of development
D) an infusion of testosterone at puberty

Question 71

During an early sensitive period, a mammal is exposed to only low levels of both androgens (such as testosterone) and estrogens (such as estradiol). How will its external genital anatomy appear?

A) about like that of a normal male
B) intermediate between male and female
C) about like that of a normal female
D) either, depending on the presence or absence of a Y chromosome

Question 72

What anatomical difference, other than sex organs, is reliably seen between males and females, even at an early age?

A) complexity of the cerebral cortex
B) size of the pituitary
C) organization of the brain stem
D) size of parts of the hypothalamus

Question 73

Parts of the hypothalamus can generate a cyclic pattern of hormone release in:

A) females only.
B) males only.
C) females and males.
D) females during childhood and males during adolescence.

Question 74

The difference between males and females in the sexually dimorphic nucleus is that it is:

A) larger in males than in females.
B) larger in females than in males.
C) present in males, absent in females.
D) present in females, absent in males.

Question 75

What would cause a young mammal's external genitals to have an appearance intermediate between a male and a female?

A) normal levels of estrogen in a genetic female
B) high levels of both testosterone and estrogen in a genetic male
C) more testosterone than other females in a genetic female
D) extra estrogen production in a genetic male

Question 76

The sexually dimorphic nucleus is part of the:

A) thalamus.
B) Wolffian ducts.
C) anterior hypothalamus.
D) male brain, only.

Question 77

If a female rat is injected with testosterone during the last few days before being born or the first few days afterward, at maturity her:

A) pituitary and ovaries will not produce their hormones.
B) ovaries will no longer produce hormones, although her pituitary will.
C) pituitary and ovaries will produce steady levels of hormones instead of cyclic levels of hormones.
D) pituitary and ovaries will produce cyclic levels of hormones instead of steady levels.

Question 78

Alcohol, marijuana, and haloperidol tend to have a(n) ____ effect on prenatal sexual development.

A) aromatic
B) defeminizing
C) masculinizing
D) demasculinizing

Question 79

The sexually dimorphic nucleus is located in the:

A) thalamus.
B) Wolffian ducts.
C) anterior hypothalamus.
D) male brain, only.

Question 80

What would cause a male mammal to develop an anatomy that looks like a female's?

A) a deficit of testosterone during puberty
B) a deficit of testosterone during an early stage of development
C) exposure to a high level of estradiol during puberty
D) exposure to a high level of estradiol during an early stage of development