- Human sperm cells first arise in theA) prostate gland.B) vas deferens.C) seminiferous tubules.D) epididymis.E) Sertoli cells.
- At the time of fertilization, the complete maturation of each oogonium has resulted inA) one secondary oocyte.B) two primary oocytes.C) four secondary oocytes.D) four primary oocytes.E) four zygotes.
- An oocyte released from a human ovary enters the oviduct as a result ofA) the beating action of the flagellum on the oocyte.B) the force of the follicular ejection directing the oocyte into the oviduct.C) the wavelike beating of cilia lining the oviduct.D) movement of the oocyte through the pulsating uterus into the oviduct.E) peristaltic contraction of ovarian muscles.
- In close comparisons, external fertilization often yields more offspring than does internal fertilization. However, internal fertilization offers the advantage thatA) it is the only way to ensure the survival of the species.B) it requires less time and energy to be devoted to reproduction.C) the smaller number of offspring produced often receive a greater amount of parental investment.D) it permits the most rapid population increase.E) it requires expression of fewer genes and maximizes genetic stability.
- Among mammals, the male and female genital structures that consist mostly of erectile tissue include theA) penis and clitoris.B) vas deferens and oviduct.C) testes and ovaries.D) seminiferous tubules and hymen.E) prostate and ovaries.
- What is the embryo-produced hormone that maintains progesterone and estrogen secretion by the corpus luteum through the first trimester of pregnancy?A) luteinizing hormone (LH)B) follicle-stimulating hormone (FSH)C) progesteroneD) human chorionic gonadotropin (HCG)E) gonadotropin-releasing hormone (GnRH)
- A primary response by the Leydig cells in the testes to the presence of luteinizing hormone is an increase in the synthesis and secretion ofA) inhibin.B) testosterone.C) oxytocin.D) prolactin.E) progesterone.
- A function-disrupting mutation in the progesterone receptor gene would likely result inA) the absence of secondary sex characteristics.B) the absence of pituitary gonadotropin hormones.C) the inability of the uterus to support pregnancy.D) enlarged and hyperactive uterine endometrium.E) the absence of mammary gland development.
- Prior to ovulation, the primary steroid hormone secreted by the growing follicle isA) LH.B) FSH.C) inhibin.D) GnRH.E) estradiol.
- The primary difference between estrous and menstrual cycles is thatA) the endometrium shed by the uterus during the estrous cycle is reabsorbed, whereas the shed endometrium of menstrual cycles is excreted from the body.B) behavioral changes during estrous cycles are much less apparent than those of menstrual cycles.C) season and climate have less pronounced effects on estrous cycles than they do on menstrual cycles.D) copulation normally occurs across the estrous cycle, whereas in menstrual cycles copulation only occurs during the period surrounding ovulation.E) most estrous cycles are of much longer duration compared to menstrual cycles.
- Most of the noncellular fluid in ejaculated human semen is composed ofA) the secretions of the seminiferous tubules.B) the secretions of the bulbourethral glands.C) the secretions of the seminal vesicles.D) the secretions of the prostate gland.E) anticoagulant enzymes.
- In correct chronological order, the three phases of the human ovarian cycle areA) menstrual → ovulation → luteal.B) follicular → luteal → secretory.C) menstrual → proliferative → secretory.D) follicular → ovulation → luteal.E) proliferative → luteal → ovulation.
- The surgical removal of the seminal vesicles would likelyA) cause sterility because sperm would not be produced.B) cause sterility because sperm would not be able to exit the body.C) greatly reduce the volume of semen.D) enhance the fertilization potency of sperm in the uterus.E) cause the testes to migrate back into the abdominal cavity.
- In vertebrate animals, spermatogenesis and oogenesis differ in thatA) oogenesis begins at the onset of sexual maturity, whereas spermatogenesis begins during embryonic development.B) oogenesis produces four haploid cells, whereas spermatogenesis produces only one functional spermatozoon.C) cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis.D) oogenesis ends at menopause, whereas spermatogenesis is finished before birth.E) spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed by the time a girl is born.
- At the end of a nonpregnant ovarian cycle, the breakdown and discharge of the soft uterine tissues is calledA) menstruation.B) lactation.C) fertilization.D) menopause.E) ovulation.
- A male's "primary" sex characteristics includeA) deepening of the voice at puberty.B) embryonic differentiation of the seminal vesicles.C) growth of skeletal muscle.D) elongation of the skeleton prior to puberty.E) onset of growth of facial hair at puberty.
- Females of many insect species, including honeybee queens, can store gametes shed by their mating partners inA) their nests B) the abdominal tract C) the cloaca D) the uterus E) the spermatheca
- During human heterosexual (mutual) excitement, vasocongestionA) occurs only in the penis.B) occurs only in the testes.C) occurs only in the clitoris.D) occurs only in the upper vagina.E) occurs in the clitoris, vagina, and penis.
- The junction of the upper vagina and the uterus is called theA) fallopian tube B) clitoris C) oviduct D) labia majora E) cervix
- Testosterone is synthesized primarily by theA) sperm cells B) hypothalamus C) Leydig cells D) anterior pituitary gland E) seminiferous tubules