Review Questions

Review Questions

Which method of reproduction produces identical offspring and is most successful in a stable environment?
  1. asexual
  2. sexual
  3. conjugation
  4. inbreeding
Which method produces genetically-unique offspring?
  1. parthenogenesis
  2. budding
  3. fragmentation
  4. sexual reproduction
Which of the following statements is FALSE?
  1. Budding is a method of asexual reproduction.
  2. Fragmentation is a method of asexual reproduction.
  3. Parthenogenesis is a type of sexual reproduction that produces diverse offspring.
  4. Binary fission is a method of asexual reproduction.
Sea stars are broken apart by workers to save the clams they feed on, and then thrown back into the ocean. Often the numbers of sea stars are seen to double after this. Give the reason why this happens.
  1. regeneration
  2. fragmentation
  3. budding
  4. the presence of suitable conditions

Which form of reproduction might be used by a sexually reproducing animal that has limited mobility?

  1. fragmentation
  2. budding
  3. hermaphroditism
  4. parthenogenesis

In sexual reproduction in mammals, gametes with either an X or Y chromosome are formed in males, whereas gametes in females have one of two possible X chromosomes. What is the nature of both male and female gametes?

  1. diploid
  2. haploid
  3. homozygous
  4. heterozygous
External fertilization most commonly occurs in which type of environment?
  1. aquatic
  2. forests
  3. savanna
  4. steppe
Why is broadcast spawning considered advantageous?
  1. Production of many eggs increases the chance of fertilization.
  2. Production of many sperm increases the chance of fertilization.
  3. It results in mixing of genes and greater genetic diversity.
  4. Animals that are motile carry out this process.
Which term applies to egg development outside the female with nourishment derived from a yolk?
  1. oviparity
  2. viviparity
  3. ovoviparity
  4. ovovoparity

How are the offspring of viviparous animals different from the offspring of oviparous animals?

  1. They are protected from the external environment.
  2. They are produced in higher numbers.
  3. They can live longer.
  4. They can use nutrients better.
Which of the following structures is involved in mating in birds?
  1. cloaca
  2. spermatheca
  3. uterus
  4. coelom
The spermatheca, which is found in many insects, worms, and mollusks, is useful for _____.
  1. spermatogenesis
  2. sperm motility
  3. growth of embryos
  4. storing sperm and as a site for fertilization
Which part of the male reproductive system produces most of the semen?
  1. scrotum
  2. seminal vesicles
  3. seminiferous tubules
  4. prostate gland
How is an oocyte released from a human ovary so it can enter the oviduct?
  1. the beating action of the flagellum on the oocyte
  2. the force of the follicular ejection directing the oocyte into the oviduct
  3. the wavelike beating of cilia lining the oviduct
  4. muscular contraction of the ovaries
Which female organ has the same embryonic origin as the penis?
  1. clitoris
  2. labia majora
  3. greater vestibular glands
  4. vagina

Which structure is only related to the male urinary system, as opposed to the male reproductive system?

  1. urinary bladder
  2. Cowper’s gland
  3. bulbourethral gland
  4. urethra

How many eggs are produced as a result of one meiotic series of cell divisions?

  1. one
  2. two
  3. three
  4. four
Which of the following events activate the germ cells at puberty to produce spermatozoa?
  1. activation by gonadotropin-releasing hormone
  2. activation by increased hair growth
  3. increase in blood volume
  4. increase of secretion of testosterone
What stimulates Leydig cells in the testes to produce testosterone?
  1. FSH
  2. LH
  3. inhibin
  4. estrogen
In both males and females, the hormones FSH and LH play a critical role in the reproductive phase. What regulates the secretion of these hormones?
  1. GnRH
  2. estrogen
  3. progesterone
  4. inhibin
Which hormone prepares the endometrial lining of the uterus for potential implantation?
  1. testosterone
  2. estrogen
  3. GnRH
  4. progesterone
With the onset of menopause, the follicles stop responding to which of the following hormones?
  1. estradiol and progesterone
  2. progesterone and estrogen
  3. FSH and LH
  4. FSH and GnRH
After ovulation, increasing amounts of _____ cause the endometrium to start to thicken.
  1. fluid
  2. LH
  3. progesterone
  4. GnRH

What characterizes the acrosomal reactions?

  1. the sperm degrades the outermost layer of the egg to penetrate it
  2. motility of the sperm
  3. fusion of the egg and sperm
  4. breakdown of the envelope covering the sperm head
What occurs as a result of fertilization of an egg and sperm?
  1. Fertilization restores diploidy.
  2. Fertilization always results in a viable embryo.
  3. Fertilization merges two diploid cells into a haploid cell.
  4. Fertilization precedes ovulation.

Which of the following statements about early embryonic stages is FALSE?

  1. The endoderm, mesoderm, and ectoderm are germ layers.
  2. The trophoblast is one of the germ layers.
  3. The inner cell mass is a source of embryonic stem cells.
  4. The blastula is often a hollow ball of cells.
Gastrulation is the process in which the cells in the blastula rearrange themselves and form three layers of cells. Each layer will differentiate into a different organ system. At what point of development do the major organs begin to develop in humans?
  1. fertilization
  2. first trimester
  3. second trimester
  4. third trimester
What happens to the number of cells during cleavage?
  1. It increases.
  2. It decreases.
  3. It doubles with every cell division.
  4. It does not change significantly.
The blastula stage is a mass of specialized cells. Of the following, which forms the liver cells?
  1. inner cell mass
  2. trophoblast
  3. the entire blastula
  4. all of the blastomeres
Which germ layer forms the skin cells?
  1. endoderm
  2. ectoderm
  3. mesoderm
  4. trophoblast
What are the three phases of embryonic development in chronological order?
  1. blastula → gastrula → cleavage
  2. blastula → cleavage → gastrula
  3. cleavage → gastrula → blastula
  4. cleavage → blastula → gastrula
Which of the following does NOT describe axes of symmetry in animals?
  1. anterior-posterior
  2. dorsal-ventral
  3. upper-lower
  4. lateral-median
Which of the following statements best summarizes the factors controlling symmetry?
  1. Genetics are important in axis formation.
  2. Body symmetry is independent of genes.
  3. Body symmetry is determined entirely at the blastula stage.
  4. Body symmetry is determined as the embryo grows in length.
The neural plate undergoes folding and movement of cells to form which structure?
  1. neural tube
  2. epidermis
  3. mesoderm
  4. neural cord
What is necessary for normal human fertilization to occur?
  1. Many eggs must be released.
  2. The uterus must be enlarged.
  3. One sperm needs to penetrate one egg.
  4. Secretion of pituitary FSH and LH must decrease.
Before pregnancy, progesterone is produced by the ovaries to thicken the endometrial lining and ensure pregnancy. During the third trimester of pregnancy, which organ produces progesterone?
  1. placenta
  2. endometrial lining
  3. chorion
  4. corpus luteum
Which hormone is primarily responsible for the contractions during labor?
  1. oxytocin
  2. estrogen
  3. β-HCG
  4. progesterone
What happens before the baby and placenta are expelled?
  1. Thinning and dilation of the cervix take place.
  2. There is increased blood flow to the baby.
  3. Enlargement of the uterus takes place.
  4. Increased production of estrogen occurs.
Which type of short-term contraceptive method is generally more effective than others?
  1. barrier
  2. hormonal implants
  3. natural family planning
  4. withdrawal
Which of the following best indicates that a female is ovulating?
  1. slight decrease in body temperature
  2. decrease in cervical volume
  3. more pliable cervical secretions
  4. change in breast size
Fertility is generally unaffected by_____.
  1. sexually transmitted diseases
  2. obstruction of reproductive tubes
  3. drug use
  4. genetic factors
What occurs in the procedure known as in vitro fertilization (IVF)?
  1. A sperm is injected into the egg externally.
  2. An egg is fertilized by the sperm internally in the oviduct.
  3. Eggs and sperm are combined externally and then implanted immediately.
  4. Egg and sperm are combined externally and the resulting embryo is implanted.