Question 1

The external reproductive organs of males and females develop

Accepted Answer

Both the external reproductive organs of males and females develop from the same bipotential tissue during embryonic development. The differentiation of these tissues into male or female external genitalia is determined by the presence or absence of specific hormones during development.

Question 2

Which of the following statements describes our current understanding of differences in the structure of human female and human male brains?

Accepted Answer

Many studies have documented structural differences between male and female brains, including differences in volume, gray and white matter density, and connectivity patterns. However, the extent and significance of these differences is still debated among researchers. Choices A, B, D, and E are inaccurate or unsupported by current research.

Question 3

Puberty is associated with an increase in the release of

Accepted Answer

During puberty, there is an increase in the release of growth hormone, adrenocorticotropic hormone (which stimulates the adrenal glands), and gonadotropic hormones (which stimulate the gonads), making all of the above correct.

Question 4

There is good evidence in some species that testosterone does not masculinize the brain directly, that it is first converted to estradiol, which then masculinizes the brain. This hypothesis is called the __________ hypothesis.

Accepted Answer

The hypothesis that testosterone is first converted to estradiol, which then masculinizes the brain is called the aromatization hypothesis. The other choices are not relevant to this particular hypothesis.

Question 5

Ear wiggling

Accepted Answer

The answer of Ear wiggling
...

Question 6

All gonadal sex hormones are

Accepted Answer

All gonadal sex hormones, such as testosterone and estrogen, are steroids and are derived from cholesterol. Therefore, the best choice is D as it includes both A and C. Choice E is incorrect because gonadal sex hormones are not peptides.

Question 7

The male and female external reproductive organs develop from the

Accepted Answer

The male and female external reproductive organs develop from a bipotential precursor, meaning that they originate from the same structure in the embryo before differentiating into either male or female genitalia. Therefore, neither the Wolffian system nor the Müllerian system alone is responsible for external genital development.

Question 8

Which of the following is a secondary sex characteristic that is induced by an androgen other than testosterone?

Accepted Answer

The answer of Which of the following is a secondary...

Question 9

In sensitive species, female fetuses are protected from the masculinizing effects of their mother's estradiol by

Accepted Answer

Alpha fetoprotein is a protein produced by the fetus that binds to estradiol in the mother's bloodstream and prevents it from crossing the placenta and masculinizing the female fetus. This allows for normal female development in sensitive species.

Question 10

Which of the following male structures develops from the same fetal tissue as do the labia majora?

Accepted Answer

The scrotum and labia majora both develop from the same fetal tissue, the genital tubercle.

Question 11

The aromatization hypothesis is that

Accepted Answer

The aromatization hypothesis suggests that estradiol created from testosterone in the brains of developing males masculinizes their brains. This is done by binding to estrogen receptors in the brain and promoting the development of male-typical neural circuits. This is supported by studies showing that blocking the conversion of testosterone to estradiol in developing male brains leads to reduced masculine behaviors and brain structures.

Question 12

Alpha fetoprotein

Accepted Answer

Alpha fetoprotein (AFP) is present in the blood of neonatal rats, does not readily penetrate the blood-brain barrier, and deactivates circulating estradiol, making all of the given statements correct.

Question 13

Generally speaking, feminization of the body at puberty

Accepted Answer

The feminization of the body during puberty is stimulated by a high ratio of estrogens to androgens. This is why estrogen levels rise in girls during puberty, leading to the development of breasts, widening of the hips, and other feminine physical characteristics. Testosterone is still present in girls during puberty, but it is typically at lower levels than estrogen.

Question 14

In the evaluation of the effects of various hormone treatments on reproductive behavior, it is important to distinguish between "feminize" and "demasculinize" because they

Accepted Answer

Feminize and demasculinize do not always go together. Feminize refers to the process of developing female characteristics, while demasculinize refers to the loss of male characteristics. These terms are not necessarily opposite to masculinize and defeminize because some hormone treatments can affect both male and female characteristics in different ways. Therefore, it is important to distinguish between these terms in order to properly evaluate the effects of hormone treatments on reproductive behavior.

Question 15

Brains of men and women exhibit the following general difference: Men's brains tend to be

Accepted Answer

Men's brains tend to be approximately 15% larger than women's brains, on average.

Question 16

At puberty, the growth of female pubic hair and axillary hair is stimulated by

Accepted Answer

The answer of At puberty, the growth of female pubic...

Question 17

If the testes of a normal male fetus were removed as soon as they developed, the child would be born with

Accepted Answer

The removal of testes in a male fetus would lead to a lack of testosterone and anti-Müllerian hormone, which are crucial for the development of male internal and external reproductive structures and the suppression of female duct development. Without these hormones, the fetus would not develop male reproductive structures, could potentially develop female internal reproductive ducts, and the hypothalamus might default to a pattern of releasing gonadotropin-releasing hormones cyclically, similar to the female pattern.

Question 18

Which of the following statements about brain differentiation is true according to recent findings?

Accepted Answer

None of the statements are true according to recent findings. Rather, brain differentiation is a complex process influenced by both genetic and environmental factors. Hormones such as testosterone and estradiol play a role in this process, but there is not a single mechanism that accounts for all differences between male and female brains. Additionally, research suggests that there may be some overlap in brain characteristics between males and females.

Question 19

A century and a half ago, puberty usually began at about __________ years of age.

Accepted Answer

Historically, puberty began later than it does today, typically around 15 or 16 years of age, due to various factors including nutrition and health conditions.

Question 20

A normal genetic female who receives injections of testosterone throughout fetal development will be born with

Accepted Answer

The answer of A normal genetic female who receives injections...

Quiz 13: Hormones and Sex