Question 1

Genetic males with 5$\alpha$-reductase deficiency may be born with ambiguous or female-like genitalia because

Accepted Answer

The enzyme 5α-reductase is responsible for converting testosterone to dihydrotestosterone (DHT), which is crucial for the development of male external genitalia in utero. A deficiency in this enzyme leads to the inability to produce DHT, resulting in ambiguous or female-like genitalia in genetic males.

Question 2

_______ is a condition in males in which the urethral folds fail to fully enclose the urethra.

Accepted Answer

Hypospadias is a condition where the opening of the urethra is not located at the tip of the penis due to incomplete closure of the urethral folds during development.

Question 3

Three months after birth, the condition of undescended testicles is called

Accepted Answer

Cryptorchidism is the condition where one or both of the testicles have not descended into the scrotum three months after birth.

Question 4

Approximately _______% of boys are affected by cryptorchidism.

Accepted Answer

Cryptorchidism is a condition in which one or both testicles fail to descend into the scrotum. It affects approximately 1% of boys.

Question 5

A sexually dimorphic cell group in the medical preoptic area of the human hypothalamus is the

Accepted Answer

INAH3, or the third interstitial nucleus of the anterior hypothalamus, has been identified as a sexually dimorphic cell group in the medial preoptic area of the human hypothalamus, showing differences in size between males and females.

Question 6

The SDN-POA is larger in _______ than in _______.

Accepted Answer

The sexually dimorphic nucleus of the preoptic area (SDN-POA) is typically larger in male rodents than in female rodents due to differences in hormone exposure during development.

Question 7

Administering testosterone to female rats during a period immediately before and after birth leads to male-typical development of the SDN-POA. Administration of testosterone to an adult female has no effect on the SDN-POA. Which of the following is the best interpretation of these results?

Accepted Answer

The results indicate that testosterone's effect on the SDN-POA is dependent on the timing of its administration, specifically during a sensitive period of development, to influence male-typical development. This suggests that testosterone's impact on the SDN-POA is not effective outside of this critical window, highlighting the importance of developmental timing for the influence of hormones on brain structure.

Question 8

When Alfred Jost removed the ovaries from female rat fetuses, the animals developed as females. However, these females were unlikely to exhibit female sexual behavior as adults because

Accepted Answer

The answer of When Alfred Jost removed the ovaries from...

Question 9

If the SRY gene "jumps" onto an X chromosomes during meiosis, the resulting XX offspring will develop as a male. The observation that these individuals have defective spermatogenesis suggests that

Accepted Answer

Other genes on the Y chromosome, besides the SRY gene, play crucial roles in male fertility, including the development and function of the testes and the production of sperm. The SRY gene is responsible for initiating male sex determination, but spermatogenesis requires additional genes located on the Y chromosome.

Question 10

The relative contributions of biological and environmental factors on sexual development have been explored in various ways, including studies of the offspring of pregnant mothers exposed to stress or hormone-related drugs, and studies of the effects of same-sex or mixed-sex housing on the development of sexual behavior in non-human primates. Which of the following statements best reflects the conclusions derived from these studies?

Accepted Answer

Environmental and biological factors both play significant roles in shaping sexual development and behavior, as evidenced by studies on the effects of prenatal exposure to stress or hormones and the impact of social environments on non-human primates. These findings suggest a complex interplay between genetics, environment, and social factors throughout life.

Question 11

Although sex hormone levels are very low in both boys and girls from around 6 to 9 months of age until puberty, there are sex differences in personality and behavior in young children. These differences are believed to be largely due to

Accepted Answer

Organizational effects of prenatal hormones are believed to be largely responsible for sex differences in personality and behavior in young children.

Question 12

Boys are generally taller than girls after puberty because the pubertal growth spurt

Accepted Answer

Girls typically start their pubertal growth spurt earlier than boys, but it lasts about the same amount of time for both genders. However, boys generally grow taller because they have a longer period of pre-pubertal growth and a greater growth spurt during puberty.

Question 13

_______ is the transition to sexual maturity.

Accepted Answer

Puberty is the period during which adolescents reach sexual maturity and become capable of reproduction.

Question 14

The pubertal growth spurt in the contemporary U.S. population starts at an average age of _______ for girls and _______ for boys.

Accepted Answer

The pubertal growth spurt typically begins around age 11 for girls and age 13 for boys in the contemporary U.S. population.

Question 15

_______ are examples of secondary sex characteristics that develop during puberty.

Accepted Answer

Secondary sex characteristics, such as the growth of body hair, changes in fat and muscle distribution, and the development of breasts in females, are physical changes that occur during puberty but are not directly involved in reproduction.

Question 16

Menstruation is often _______ for the first year or two after menarche, and during this period menstrual cycles tend to be _______.

Accepted Answer

Menstruation is often irregular for the first year or two after menarche (the first menstrual cycle), and during this period, menstrual cycles tend to be anovulatory, meaning ovulation does not occur. This is a normal part of the reproductive system's maturation process.

Question 17

Which of the following is not an early sign of puberty for boys?

Accepted Answer

Early signs of puberty in boys typically include enlargement of the testes and penis, a change in voice, and sometimes gynecomastia (development of breast tissue). A drop in testosterone levels is not an early sign of puberty; in fact, testosterone levels increase during puberty.

Question 18

Among females in the U.S. population, which group is the earliest to show visible signs of puberty?

Accepted Answer

African-American girls, on average, begin puberty earlier than girls from other racial or ethnic groups in the United States. This includes the development of secondary sexual characteristics such as breast development and the onset of menstruation.

Question 19

Estrogens play many important roles during puberty. Which of the following characteristics would not be expected in a girl who could not produce estrogen or lacked estrogen receptors?

Accepted Answer

Estrogen is crucial for the closure of growth plates in bones, so a lack of estrogen would result in continued growth and potentially taller stature, not shorter.

Question 20

Which of the following is not thought to contribute to the timing of the onset of puberty?

Accepted Answer

Societal pressure is not a biological factor and does not directly influence the physiological timing of puberty onset.

Quiz 6: Sexual Development

Genetic males with 5 $\alpha$ -reductase deficiency may be born with ambiguous or female-like genitalia because

_______ is a condition in males in which the urethral folds fail to fully enclose the urethra.

Three months after birth, the condition of undescended testicles is called

Approximately _______% of boys are affected by cryptorchidism.

A sexually dimorphic cell group in the medical preoptic area of the human hypothalamus is the

The SDN-POA is larger in _ than in _.

Administering testosterone to female rats during a period immediately before and after birth leads to male-typical development of the SDN-POA. Administration of testosterone to an adult female has no effect on the SDN-POA. Which of the following is the best interpretation of these results?

When Alfred Jost removed the ovaries from female rat fetuses, the animals developed as females. However, these females were unlikely to exhibit female sexual behavior as adults because

If the SRY gene "jumps" onto an X chromosomes during meiosis, the resulting XX offspring will develop as a male. The observation that these individuals have defective spermatogenesis suggests that

Although sex hormone levels are very low in both boys and girls from around 6 to 9 months of age until puberty, there are sex differences in personality and behavior in young children. These differences are believed to be largely due to

Boys are generally taller than girls after puberty because the pubertal growth spurt

_______ is the transition to sexual maturity.

The pubertal growth spurt in the contemporary U.S. population starts at an average age of _ for girls and _ for boys.

_______ are examples of secondary sex characteristics that develop during puberty.

Menstruation is often _ for the first year or two after menarche, and during this period menstrual cycles tend to be _.

Which of the following is not an early sign of puberty for boys?

Among females in the U.S. population, which group is the earliest to show visible signs of puberty?

Estrogens play many important roles during puberty. Which of the following characteristics would not be expected in a girl who could not produce estrogen or lacked estrogen receptors?

Which of the following is not thought to contribute to the timing of the onset of puberty?

Quiz 6: Sexual Development

Genetic males with 5 α\alphaα -reductase deficiency may be born with ambiguous or female-like genitalia because

_______ is a condition in males in which the urethral folds fail to fully enclose the urethra.

Three months after birth, the condition of undescended testicles is called

Approximately _______% of boys are affected by cryptorchidism.

A sexually dimorphic cell group in the medical preoptic area of the human hypothalamus is the

The SDN-POA is larger in _______ than in _______.

Administering testosterone to female rats during a period immediately before and after birth leads to male-typical development of the SDN-POA. Administration of testosterone to an adult female has no effect on the SDN-POA. Which of the following is the best interpretation of these results?

When Alfred Jost removed the ovaries from female rat fetuses, the animals developed as females. However, these females were unlikely to exhibit female sexual behavior as adults because

If the SRY gene "jumps" onto an X chromosomes during meiosis, the resulting XX offspring will develop as a male. The observation that these individuals have defective spermatogenesis suggests that

Although sex hormone levels are very low in both boys and girls from around 6 to 9 months of age until puberty, there are sex differences in personality and behavior in young children. These differences are believed to be largely due to

Boys are generally taller than girls after puberty because the pubertal growth spurt

_______ is the transition to sexual maturity.

The pubertal growth spurt in the contemporary U.S. population starts at an average age of _______ for girls and _______ for boys.

_______ are examples of secondary sex characteristics that develop during puberty.

Menstruation is often _______ for the first year or two after menarche, and during this period menstrual cycles tend to be _______.

Which of the following is not an early sign of puberty for boys?

Among females in the U.S. population, which group is the earliest to show visible signs of puberty?

Estrogens play many important roles during puberty. Which of the following characteristics would not be expected in a girl who could not produce estrogen or lacked estrogen receptors?

Which of the following is not thought to contribute to the timing of the onset of puberty?

Genetic males with 5 $\alpha$ -reductase deficiency may be born with ambiguous or female-like genitalia because

The SDN-POA is larger in _ than in _.

The pubertal growth spurt in the contemporary U.S. population starts at an average age of _ for girls and _ for boys.

Menstruation is often _ for the first year or two after menarche, and during this period menstrual cycles tend to be _.