Deck 3: Sex Differences in Behavior: Sex Determination and Differentiation

Question 1

What makes a particular tissue a "target tissue" for hormones?

A) It has DNA, RNA, and proteins.
B) It grows in response to hormonal treatment.
C) It has proteins that bind to the hormone.
D) Gene transcription is closely regulated.

Answer 1

C

Question 2

The process of becoming male or female is called sexual

A) differentiation.
B) maturation.
C) reproduction.
D) determination.

Answer 2

A

Question 3

Which of the following suggests that intrauterine endocrine environment influences sexually dimorphic behaviors of adults?

A) Female mice that had two males as neighbors in utero are more aggressive as adults than female mice that had no males as neighbors.
B) If >3 females are present in a litter, then all males in the litter are feminized.
C) If >3 males are present, then female Wolffian duct development occurred.
D) If males had two females as neighbors in utero, then they are more aggressive as adults than males that had two males as neighbors.

Answer 3

A

Question 4

A genetic male rat that is castrated on day 3 of life will show which behavior in adulthood?

A) Mounting behavior when given estradiol
B) Lordosis behavior when given estradiol followed by progesterone
C) Lordosis behavior when given DHT
D) Mounting behavior when given DHT

Question 5

Which of the following about freemartins is not true?

A) About 90 percent of female cattle born as twins to males are freemartins.
B) It is relatively easy to produce freemartins experimentally.
C) The gonads are atrophied in freemartins.
D) External genitalia of freemartins is of the female type.

Question 6

Visible sexual dimorphisms are most prominent in species characterized by

A) polygamy.
B) monogamy.
C) parthenogenesis.
D) feathers or scales.

Question 7

"Masculinization" of the mammalian brain can occur via

A) aromatization of estradiol into testosterone.
B) α-fetoprotein or albumin reaching the brain.
C) aromatization of testosterone into estradiol.
D) expression of the W chromosome.

Question 8

The possession of gonads is called

A) gonadal sex.
B) chromosomal sex.
C) phenotypic sex.
D) gender identity.

Question 9

The sex or gender that individuals feel themselves to be is called

A) gonadal sex.
B) chromosomal sex.
C) phenotypic sex.
D) gender identity.

Question 10

The penis and clitoris develop from the

A) labial folds.
B) genital tubercle.
C) bulbocavernosus.
D) Wolffian duct system.

Question 11

α-fetoprotein binds and sequesters

A) testosterone.
B) estrogens.
C cortisol.
D) DHT.

Question 12

What is the correct order in which sex determination occurs?

A) Chromosomal sex, gonadal sex, hormonal sex, morphological sex
B) Chromosomal sex, hormonal sex, morphological sex, gonadal sex
C) Gonadal sex, morphological sex, chromosomal sex, hormonal sex
D) Chromosomal sex, morphological sex, hormonal sex, gonadal sex

Question 13

In which animals can temperature-dependent sex determination be overridden by steroid treatment?

A) Kangaroos
B) Alligators
C) Birds
D) Humans

Question 14

Precocial young

A) can thermoregulate independently.
B) are born furless.
C) have a short gestational period.
D) Both a and c

Question 15

_______ prevent(s) the masculinization of the female brain by sequestering and degrading _______.

A) $\alpha$ -fetoprotein; circulating estrogens
B) 5 $\alpha$ -reductase; androgens
C) Aromatase; cortisol
D) Estrogens; androgens

Question 16

SDN-POA (sexually dimorphic nucleus of the preoptic area) is bigger in male rats than in females. This difference means that

A) males are better at visual/spatial tasks than females.
B) males are more invested in sexual behaviors than females.
C) the organizational/activational hypothesis is right.
D) None of the above; the meaning of this difference is still unknown.

Question 17

An XY male rat lacking the aromatase enzyme will likely have

A) a smaller brain than unaffected males.
B) a brain that is not completely masculinized.
C) ovaries.
D) feminized external genitalia.

Question 18

Describe an example of behavior affecting hormones.

Question 19

What enzymes are responsible for the conversion of testosterone into DHT and estradiol, respectively?

Question 20

List one female (XX) and one male (XY) example of anomalous sexual differentiation and provide two characteristics associated with each.

Question 21

How might sexual differentiation of the brain occur independently of hormones?

Question 22

SEQ CHAPTER \h \r 1Among mammals, females are considered the neutral sex with respect to sexual differentiation of the reproductive system. (a) Why is this? (b) Review the role of hormones in the differentiation of the internal sexual accessory structures (Müllerian and Wolffian ducts) and of the external genitalia. (c) Reproductive behavior undergoes sexual differentiation. Is the process of sex behavioral differentiation analogous to the sexual differentiation of the accessory organs or the external genitalia? Explain your answer.

Question 23

What effect can intrauterine environment have on sexual differentiation of brain and the subsequent expression of sexually dimorphic behaviors (mammals)?

Question 24

Describe the different levels of sex determination and differentiation.

Question 25

Explain some of the differences appearing in adulthood between female rodents gestated in the 2-M versus 0-M intrauterine position.

Question 26

Define monogamy. What evidence suggests that humans are not monogamous?

Question 27

How did the zebra finch gynandromorph add to behavioral endocrinologists' understanding of sexual differentiation?