Question 1

Sex hormones are

Accepted Answer

Sex hormones are synthesized from cholesterol, which is a steroid precursor. Therefore, the correct answer is D - steroids, because they are synthesized from cholesterol.

Question 2

Children with 5-alpha-reductase deficiency are usually

Accepted Answer

Children with 5-alpha-reductase deficiency are unable to convert testosterone to dihydrotestosterone, which is necessary for male genital development. As a result, they are typically born with female external genitalia and are raised as girls. However, at puberty, when testosterone levels increase, they may experience masculinization and develop male secondary sexual characteristics. This can lead them to identify as males and pursue a male gender identity, despite being raised as girls. Therefore, choice C is the most accurate option.

Question 3

When Anita was 10 years old,she was the tallest girl in her fourth grade class.She also began to menstruate when she was 10 years old.Given what we know about the effects of estradiol,we can expect that at age 17,Anita will be

Accepted Answer

While estradiol does play a role in growth and development during puberty, it does not continue to have a significant effect on height after growth plates have closed. Therefore, Anita is not likely to be much taller than she was at age 10. The other choices are not supported by evidence or logic.

Question 4

Release of FSH

Accepted Answer

FSH (follicle-stimulating hormone) is responsible for promoting the maturation of follicles in the ovary. These follicles contain eggs, and once they are mature, they can be released during ovulation. FSH does not directly stimulate ovulation, but it is necessary for the follicle maturation that precedes ovulation. FSH also does not directly affect the uterus or the corpus luteum.

Question 5

Human beings show

Accepted Answer

Human beings show mild trends toward seasonality in birth rates. This means that there is a slight tendency for more babies to be born during certain months of the year, although this trend is not very strong. Factors such as changes in day length, temperature, and social factors may contribute to these variations in birth rates.

Question 6

The hypothalamus controls the release of sex hormones by secreting

Accepted Answer

The hypothalamus controls the release of sex hormones by secreting Gonadotropin-releasing hormone (GnRH), which stimulates the anterior pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones, in turn, stimulate the release of sex hormones from the ovaries and testes. Melatonin is produced by the pineal gland and is involved in regulating sleep-wake cycles, not sex hormone release. 5-alpha reductase is an enzyme involved in converting testosterone to dihydrotestosterone but is not directly involved in sex hormone release.

Question 7

The corpus luteum releases

Accepted Answer

The corpus luteum is formed from the remnants of the follicle that released the egg during ovulation. It secretes estradiol and progesterone, which are the hormones that support implantation and early pregnancy. LH and FSH are hormones that stimulate the development of the follicle, but they are not released by the corpus luteum. Testosterone is primarily produced by the testes in males, but small amounts are also produced by the ovaries in females.

Question 8

Lauren was excited to go shopping for new clothes before starting middle school,but she was surprised to find out that she suddenly needed to shop in the juniors section instead of the children's section.The most likely explanation for this change is that

Accepted Answer

Lauren's sudden need to shop in the juniors section instead of the children's section is most likely due to her going through puberty, which is associated with changes in body fat distribution. Increased estradiol levels in girls during puberty cause fat to accumulate in the hips, thighs, and breasts, resulting in a more "curvy" or feminine shape. This is a normal part of development for girls and is not related to excessive snacking or exposure to synthetic hormones. The increased levels of 5-alpha reductase mentioned in choice D are more relevant to the development of male sexual characteristics, such as facial hair and a deeper voice.

Question 9

In cases of 5-alpha-reductase deficiency,_________ external genitalia at birth become _________ at puberty.

Accepted Answer

The answer of In cases of 5-alpha-reductase deficiency,_________ external genitalia...

Question 10

Estrogens are produced by

Accepted Answer

While estrogens are most commonly associated with females, they are actually produced by both males and females. However, females do produce higher levels of estrogen than males.

Question 11

During his freshman year at a college far from home,James wrote home frequently asking for more money for clothes,as he was continuing to grow taller.His father thought James was just responding to peer pressure,but his mother,a physician,pointed out that it was likely that James was really still growing because he had

Accepted Answer

Going through puberty later than most peers is a common reason why someone may continue to grow taller during their freshman year of college. This is due to delayed bone growth and development, which can result in a longer period of growth. Turner syndrome and CAH are genetic conditions, and there is no information provided that suggests James has either of these conditions. Going through puberty earlier than peers would not result in continued growth during college as growth usually stops around the age of 18-20.

Question 12

Skeletal growth is slowed by

Accepted Answer

Skeletal growth is slowed by estradiol in both males and females. Estrogens (such as estradiol) and androgens (such as testosterone) both play important roles in regulating bone growth and development, but estradiol has a greater impact on skeletal growth and the closure of the growth plates in both males and females. Testosterone also plays a role in skeletal growth, but has a more pronounced effect on muscle mass and strength.

Question 13

In the absence of sufficient quantities of 5-alpha-reductase

Accepted Answer

In the absence of sufficient quantities of 5-alpha-reductase, testosterone is not converted into 5-alpha-dihydrotesterone. This means that external genitalia are not masculinized in the fetus, because 5-alpha-dihydrotestosterone is required for the development of male genitalia. The internal organs, however, are still masculinized because this process does not rely on 5-alpha-dihydrotestosterone.

Question 14

At puberty,FSH and LH

Accepted Answer

At puberty, FSH and LH stimulate the release of additional testosterone by the testes and the release of estradiol by the ovaries. This results in the development of secondary sexual characteristics in both males and females. In males, testosterone is responsible for the growth of facial and body hair, deepening of the voice, and muscle development. In females, estradiol is responsible for breast development, widening of the hips, and onset of menstruation.

Question 15

The release of GnRH by the hypothalamus is

Accepted Answer

The release of GnRH by the hypothalamus is inhibited by melatonin and stimulated by light. Melatonin inhibits GnRH release by suppressing the activity of the hypothalamus, while light has an opposite effect on the hypothalamus and stimulates the release of GnRH. This is why the sleep-wake cycle affects the release of GnRH and, subsequently, the secretion of reproductive hormones.

Question 16

In cases of 5-alpha-reductase deficiency,internal organs

Accepted Answer

In cases of 5-alpha-reductase deficiency, the internal organs develop in the normal male pattern. This is because the body cannot convert testosterone to dihydrotestosterone, which is necessary for the development of the male external genitalia. However, the internal reproductive organs still develop in the male pattern. This means that individuals with 5-alpha-reductase deficiency may have male internal organs but female external genitalia.

Question 17

The gonadotropins are released by the

Accepted Answer

The gonadotropins (FSH and LH) are released by the anterior pituitary gland. The hypothalamus releases GnRH, which stimulates the release of gonadotropins from the anterior pituitary gland. The pineal gland secretes melatonin, which helps regulate sleep-wake cycles. The posterior pituitary gland releases oxytocin and vasopressin, which control water balance and uterine contractions during childbirth.

Question 18

The quantity of androgens produced by females is about _________ percent of the quantity produced by males.

Accepted Answer

The answer of The quantity of androgens produced by females...

Question 19

Release of LH

Accepted Answer

The answer of Release of LH
...

Question 20

In males at puberty,sperm production is regulated by

Accepted Answer

Sperm production in males at puberty is regulated by the hormones LH, FSH, and testosterone. LH and FSH are released from the pituitary gland in response to gonadotropin-releasing hormone (GnRH) from the hypothalamus. LH stimulates Leydig cells in the testes to produce testosterone, which in turn stimulates the Sertoli cells in the seminiferous tubules to support spermatogenesis. FSH also acts on the Sertoli cells to promote the maturation of sperm cells. Together, these hormones create a feedback loop that regulates the production of sperm.

Quiz 10: Sexual Behavior