11.1 Flashcards
- Although harmful in excessive amounts, the synthesis of steroids depends on:
a. heavy materials.
b. cholesterol.
c. ethanol.
d. insulin.
b. cholesterol
- 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.
d. androgens and estrogens
- 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.
d. entering cells and affecting gene expression.
- 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.
b. both sexes have both types of hormones
- “Male hormones” are referred to as:
a. activating hormones.
b. SRY.
c. androgens.
d. estrogens.
c. androgens
- “Female hormones” are referred to as:
a. activating hormones.
b. SRY.
c. androgens.
d. estrogens.
d. estrogens
- _____ prepares the uterus for pregnancy.
a. Testosterone
b. Androgen
c. Progesterone
d. Estradiol
c. progesterone
- 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.
b. during early stages in development
An organizing effect differs from an activating effect of a hormone in that an organization effect:
a. inhibits the effects of another hormone.
b. lasts only briefly.
c. activates excitatory receptors.
d. produces more long-lasting effects.
d. prodeuces more long-lasting effects
- 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.
c. masculinization of the brain.
- 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.
a. are shorter-term
- 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.
c. female and male fetuses early in development
- 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.
b. The sex region y (SRY) gene
- 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.
d. male reproductive structures
- What determines whether a mammal develops male or female external genitals?
a. The amount of testosterone during prenatal development.
b. The amount of estrogen 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.
a. The amount of testosterone during prenatal development
- What develops from the Müllerian ducts?
a. The bladder and the urethra.
b. Peripheral nerves controlling the genitals.
c. Female reproductive structures.
d. Male reproductive structures.
c. Female reproductive structures
- The result of all the testosterone-induced changes during sexual differentiation is:
a. The bladder and the urethra.
b. Peripheral nerves controlling the genitals.
c. Female reproductive structures.
d. Male reproductive structures.
d. Male reprooductive structures.
- 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
a. a single unisex structure; seprate structures
- 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.
c. a high level or testosterone during early an early stage of develpment.
- 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.
c. female and male fetuses early in development.
- 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.
b. the third and fourth months of gestation.
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.
c. putuitary and ovaries will produce steady levels of hormones instead of cyclic levels of hormones
- 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.
d. it prevents testosterone from having its usual effects.
- 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 age 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.
b. a deficit of testosterone during an early stage of develoment.
- 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.
a. exposure to high levels of testosterone durig and early stage of development
- 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.
b. female.