Sexual reproduction includes a reproductive pattern called _____.
A) fission
B) fragmentation
C) budding
D) regeneration
E) hermaphroditism
E
Regeneration, the regrowth of lost body parts, normally follows _____.
A) fission
B) fragmentation
C) all types of asexual reproduction
D) parthenogenesis
B
Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process occurs to generate this type of offspring?
A) cell fusion
B) meiosis
C) mitosis
C
On a submarine expedition to the ocean bottom, you discover a population of fish that are only female. What type of reproduction does this fish most likely use?
A) parthenogenesis
B) sexual
C) cloning
D) budding
A
Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because _____.
A) more genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually
B) sexually reproducing organisms can produce more offspring in a given time than can asexually reproducing organisms
C) asexually reproducing organisms have more dominant genes than organisms that reproduce sexually
D) asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring
D) asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring
Asexual reproduction results in greater reproductive success than does sexual reproduction when _____.
A) there is some potential for rapid overpopulation
B) a species is in stable and favorable environments
C) pathogens are rapidly diversifying
D) a species is expanding into diverse geographic settings
B
Sexual reproduction _____.
A) guarantees that both parents will provide care for each offspring
B) allows animals to conserve resources and reproduce only during optimal conditions
C) can produce diverse phenotypes that may enhance survival of a population in a changing environment
D) enables males and females to remain isolated from each other while rapidly colonizing habitats
C) can produce diverse phenotypes that may enhance survival of a population in a changing environment
Animals utilizing external fertilization are typically _____.
A) insects
B) land animals
C) aquatic animals
D) mammals
E) animals that reproduce asexually
C
In close comparisons, external fertilization often yields more offspring than does internal fertilization. However, internal fertilization typically offers the advantage that _____.
A) it requires expression of fewer genes and maximizes genetic stability
B) the smaller number of offspring produced often receive a greater amount of parental investment
C) it permits the most rapid population increase
D) it requires less time and energy to be devoted to reproduction
B) the smaller number of offspring produced often receive a greater amount of parental investment
Which of the following correctly traces the path of sperm from their site of production to their exit from a man's body?
A) seminiferous tubule → epididymis → vas deferens → urethra
B) epididymis → seminiferous tubule → vas deferens → urethra
C) epididymis → urethra → seminiferous tubule → vas deferens
D) seminiferous tubule → vas deferens → epididymis → urethra
E) vas deferens → epididymis → urethra → seminiferous tubule
A) seminiferous tubule → epididymis → vas deferens → urethra
Which of the following structures in females is analogous in function to the vas deferens in males?
A) vagina
B) oviduct
C) urethra
D) uterus
B
In humans, the follicular cells that remain behind in the ovary following ovulation become _____.
A) the placenta, which secretes cervical mucus
B) a steroid-hormone synthesizing structure called the corpus luteum
C) the ovarian endometrium that is shed at the time of the menses
D) the thickened portion of the uterine wall
B
Mature human sperm and ova are similar in that they _____.
A) each have a flagellum that provides motility
B) are approximately the same size
C) are produced from puberty until death
D) both have the same number of chromosomes
D
Among human males, both semen and urine normally travel along the _____.
A) seminal vesicle
B) ureter
C) urethra
D) vas deferens
C
Increasing the temperature of the human scrotum by 2°C (that is, near the normal body core temperature) and holding it there would most likely_____.
A) reduce the fertility of the man by impairing the production of gonadal steroid hormones
B) increase the fertility of the affected man by enhancing the rate of steroidogenesis
C) reduce the fertility of the man by impairing spermatogenesis
D) reduce the man's sexual interest
C) reduce the fertility of the man by impairing spermatogenesis
The primary difference between estrous and menstrual cycles is that _____.
A) copulation normally occurs across the estrous cycle, whereas in menstrual cycles copulation only occurs during the period surrounding ovulation
B) the endometrium shed by the uterus during the estrous cycle is reabsorbed with no extensive fluid flow out of the body, whereas the shed endometrium of menstrual cycles is excreted from the body
C) season and climate have less pronounced effects on estrous cycles than they do on menstrual cycles
D) behavioral changes during estrous cycles are much less apparent than those of menstrual cycles
B) the endometrium shed by the uterus during the estrous cycle is reabsorbed with no extensive fluid flow out of the body, whereas the shed endometrium of menstrual cycles is excreted from the body
A primary response by the Leydig cells in the testes to the presence of luteinizing hormone is an increase in the synthesis and secretion of _____.
A) testosterone
B) oxytocin
C) inhibin
D) progesterone
A
The anatomical location for the typical union of a sperm and an egg (conception) is the _____.
A) oviducts
B) vagina
C) ovaries
D) uterus
E) clitoris
A
Two contraceptive methods that are generally irreversible and which block the gametes from moving to a site where fertilization can occur are _____.
A) vasectomy and tubal ligation
B) the male condom and oral contraceptives
C) the diaphragm and subcutaneous progesterone implant
D) the male condom and female condom
A
An ectopic pregnancy occurs when a fertilized egg implants somewhere other than in the lining of the uterus. Usually it implants in the oviduct. Which of the following would be the most likely explanation for such a pregnancy being unsuccessful?
A) The orientation of the baby would be sideways.
B) The lining of the oviduct is unable to support the developing fetus.
C) The necessary hormones cannot reach the developing fetus in the oviduct.
D) Human chorionic gonadotropin (hCG) cannot be produced in the oviduct.
B
In male mammals, excretory and reproductive systems share
A) the urethra.
B) the prostate.
C) the vas deferens.
D) the testes.
E) the seminal vesicle.
A
During human gestation, rudiments of all organs develop
A) in the first trimester.
B) while the embryo is in the oviduct.
C) during the blastocyst stage.
D) in the third trimester.
E) in the second trimester.
A
Salamander and insect populations consisting only of genetically identical females lack males because _____.
A) a sex-linked, dominant, lethal mutation is fixed in the population
B) sperm do not fuse with eggs during reproduction, but the eggs develop into embryos anyway
C) a mutation in the population has eliminated the salamander equivalent of the Y chromosome
D) males are killed at birth by their mothers
E) these ancient forms preceded sexual evolution
B
In humans, oogenesis in comparison to spermatogenesis is different in that _____.
A) oogenesis does not complete meiosis until after fertilization, but spermatogenesis is complete before the sperm leave the body
B) oogenesis continues throughout life, but spermatogenesis typically ends at age 55 years
C) female puberty typically occurs much later than the age of male puberty
D) oocyte production works best at cooler temperatures than those that support spermatogenesis
E) the names and chemical identities of the pituitary hormones are completely different between males and females
A
Human sperm cells first arise in the _____.
A) prostate gland
B) seminiferous tubules
C) vas deferens
D) epididymis
B
For which of the following is the number the same in spermatogenesis and oogenesis?
A) different cell types produced by meiosis
B) timing of meiotic divisions
C) meiotic divisions required to produce each gamete
D) functional gametes produced by meiosis
C
A fertilized egg usually implants itself and develops in the _____.
A) uterus
B) ovary
C) oviduct
D) abdominal cavity
E) none of these
A
A rapid increase in the _____ level stimulates ovulation.
A) progesterone
B) estrogen
C) luteinizing hormone
D) follicle-stimulating hormone
E) human chorionic gonadotropin
C
After ovulation, high levels of _____ inhibit _____ secretion.
A) estrogen and progesterone ... FSH and LH
B) FSH and LH ... estrogen and progesterone
C) HCG ... estrogen and progesterone
D) estrogen ... FSH
E) androgens ... FSH and LH
A
Developing ovarian follicles primarily secrete _____.
A) progesterone
B) estrogens
C) luteinizing hormone
D) follicle-stimulating hormone
E) human chorionic gonadotropin
B
If there is fertilization, secretion of _____ by the early embryo maintains the corpus luteum.
A) progesterone
B) estrogen
C) luteinizing hormone
D) follicle-stimulating hormone
E) human chorionic gonadotropin
E
If there is no fertilization, degeneration of the corpus luteum results in a drop in _____, which results in the sloughing off of the uterus's endometrium.
A) FSH
B) estrogen and progesterone
C) hypothalamic secretion of releasing hormones
D) HCG
E) LH
B
Ovulation usually occurs on or about day _____ of a 28-day ovarian cycle.
A) 1
B) 7
C) 14
D) 21
E) 28
C
What is the usual site of the fertilization of an egg cell?
A) uterus
B) ovary
C) oviduct
D) abdominal cavity
E) vagina
C
A reproductive hormone that is secreted directly from a structure in the brain is _____.
A) gonadotropin-releasing hormone (GnRH)
B) progesterone
C) follicle-stimulating hormone (FSH)
D) estradiol
A