Q&A Hero

Q: An egg is not a gamete.

Q: Ovulation refers to growth of the primary follicle.

Q: Ejaculation initially deposits the sperm in the uterus.

Q: Fallopian tube is another name for the uterine tube.

Q: As sperm are made, they travel through the vas deferens and are stored in the seminal vesicles until ejaculation.

Q: Semen is the mixture of sperm and secretions from male reproductive glands.

Q: Normally, anywhere from one to four sperm fertilize the egg.

Q: How much does the cervix ultimately dilate during labor? A) 10 centimeters B) 5 centimeters C) 3 centimeters D) 1 centimeter

Q: What is the "afterbirth" associated with the birth process? A) the amniotic fluid B) the blood lost from the uterus in the weeks after birth C) the placenta D) the process of cutting the umbilical cord

Q: Which hormone stimulates the muscular contractions associated with birth of a child? A) estrogen B) progesterone C) luteinizing hormone D) oxytocin

Q: In the human birth process, what does labor refer to? A) the period between birth and expulsion of the placenta B) the period between the first contraction and dilation of the cervix C) the last part of the process when the fetus is expelled from the vagina D) regular contractions of uterine muscles

Q: How many sperm participate in the formation of fraternal twins? A) one B) two C) three D) four

Q: Why is production of lung surfactant important for a baby? A) Without lung surfactant, the baby's lungs do not develop properly. B) Lung surfactant may block the placenta from exchanging oxygen. C) Lung surfactant keeps the lung sacs from collapsing. D) Lung surfactant keeps the lungs from sticking to the diaphragm.

Q: When does the fetus achieve about 15 percent of its birth weight and start kicking? A) at the end of embryonic phase B) at the start of organogenesis C) in the first trimester D) in the second trimester E) in the third trimester

Q: Which of these becomes the baby? A) outer cell mass B) trophoblast C) inner cell mass D) placenta

Q: Which of the following best describes the period during which the developing offspring is considered a fetus? A) from fertilization to three weeks B) from fertilization to eight weeks C) the first trimester only D) the third trimester only E) from nine weeks until birth

Q: Immature versions of all the major organ systems have formed by about what point in pregnancy? A) 16 days B) 3 weeks C) 12 weeks D) not until at least 30 weeks

Q: Three weeks after conception, which of the following has happened in an embryo? A) organ formation B) neural tube formation C) limb bud formation D) primitive eye formation

Q: An ectopic pregnancy is: A) implantation of the embryo in the uterus. B) another name for fraternal twins. C) another name for identical twins. D) attachment of an embryo outside the uterus.

Q: What prevents multiple sperm from fertilizing one egg? A) release of granules that harden the membrane outside of the oocyte B) atresia C) phagocytosis by accessory cells once one sperm contacts the membrane D) egg immediately divides and becomes impervious to sperm

Q: Which of the following statements concerning sperm and fertilization is correct? A) The first sperm that approaches the egg is the one to fertilize the egg. B) Many sperm release their enzymes before one can get through. C) The first capacitated sperm fertilizes the egg. D) Several sperm must contribute their DNA to the egg for fertilization to occur.

Q: The portion of a sperm that carries enzymes needed for fertilization is the: A) tail. B) nucleus. C) acrosome. D) mitochondrion.

Q: A man has been experiencing reduced urine flow problems. After examination by his doctor, the diagnosis is an enlarged prostate gland. What is the connection between prostate enlargement and reduced urine flow? A) The prostate is located where the ureters enter the bladder. B) The prostate surrounds the urethra, the tube that transmits sperm and urine. C) An enlarged prostate is a sign of cancer that affects the kidneys. D) An enlarged prostate is a sign of cancer that affects the bladder.

Q: Why is it useful for accessory glands to produce alkaline substances to accompany sperm? A) Alkaline substances neutralize the acidic environment of the vagina. B) Alkaline substances produce a pH optimum for nutrient absorption. C) Alkaline substances are mainly fats used for energy. D) Alkaline substances function as enzymes needed for swimming.

Q: A fertility doctor is trying to determine why a couple is infertile. It has been determined that the woman is fertile, so the problem may be with the man. In analyzing his semen, the doctor notices adequate sperm production, but the sperm are largely inactive. He concludes that the semen may be lacking in proper nutrients for the sperm. Which structure would be the most likely candidate for the source of the problem? A) urethra B) seminiferous tubules C) vas deferens D) seminal vesicles

Q: Sperm development takes about: A) 1 month. B) 28 days. C) 6 months. D) 2.5 months.

Q: When a spermatogonium divides, it produces one primary spermatocyte and: A) two secondary spermatocytes. B) one spermatogonium. C) one spermatid. D) one nurse cell.

Q: The sequence of development of sperm is: A) primary spermatocyte, secondary spermatocyte, tertiary spermatocyte, spermatid, sperm. B) primary spermatocyte, spermatogonia, sperm. C) immature sperm, mature sperm, secondary sperm, spermatocyte. D) spermatogonia, spermatocyte, spermatid, sperm.

Q: Development of sperm occurs from the: A) inside of the seminiferous tubule toward the outside. B) outside of the epididymis toward the inside. C) outside of the seminiferous tubule toward the inside. D) middle of the penis toward the prostate gland.

Q: Which of these is not a supporting gland in males? A) prostate gland B) seminal vesicle C) epididymis D) bulbourethral gland

Q: The vas deferens ducts empty sperm into the: A) seminal vesicles. B) epididymis. C) uterus. D) urethra.

Q: Sperm development begins in the: A) prostate gland. B) seminiferous tubules. C) epididymis. D) vas deferens.

Q: Spermatids are produced by: A) spermatogonia. B) primary spermatocytes. C) secondary spermatocytes. D) sertiary spermatocytes.

Q: Which statement concerning gamete production is correct? A) Sperm cells can be produced only at certain points in the reproductive cycle. B) The number of sperm a man can produce is essentially unlimited, whereas the number of eggs a woman can potentially produce is limited. C) A man is born with all of the sperm he will need for the rest of his life. D) Progestins stimulate development of new follicles.

Q: Why does a female have millions of ovarian follicles as a fetus but has perhaps just over a thousand in her early fifties? A) Several hundred follicles ovulate per monthly cycle and deplete the follicle supply at a steady rate. B) Several thousand follicles ovulate per monthly cycle and deplete the follicle supply at a steady rate. C) Natural degeneration of follicles speeds up in later years. D) Production of new follicles from stem cells slows in her fifties.

Q: From which structure does the corpus luteum develop? A) oocyte B) tertiary follicle C) primary follicle D) secondary follicle

Q: Which structure would be best described as helping to prepare the female tract for pregnancy and maintain it during the early phases of pregnancy? A) vagina B) uterine tube C) oocyte D) corpus luteum

Q: What changes occur in the endometrium as the time of possible fertilization approaches? A) Menstruation occurs. B) The endometrium enters the proliferative phase. C) The endometrium enters the secretory phase. D) The endometrium secretes estrogen.

Q: Fraternal twins develop when: A) one egg is fertilized by two sperm. B) two eggs are fertilized by one sperm. C) multiple ovulations occur, and two eggs are fertilized. D) one egg is fertilized by one sperm, but the resulting cells separate from one another and continue development.

Q: The stages of follicle development are: A) tertiary follicle, secondary follicle, primary follicle, corpus luteum. B) ovarian follicle, mature follicle, oocyte. C) corpus luteum, tertiary follicle, secondary follicle, primary follicle. D) primary follicle, secondary follicle, tertiary follicle, corpus luteum.

Q: The specialized tissue of the uterus where implantation occurs is the: A) cervix. B) vagina. C) endometrium. D) uterine tube.

Q: Implantation occurs in the: A) ovary. B) vagina. C) uterine tube. D) uterus.

Q: Which of the following is a structure in which sperm mature and are stored? A) vas deferens B) testis C) accessory glands D) epididymis

Q: Sperm are made in the: A) testes. B) epididymis. C) ovary. D) vas deferens.

Q: On average, about how often does ovulation occur? A) every 6 months B) every 28 days C) every 14 days D) every day

Q: Through what structure does an oocyte travel on its way to the uterus? A) uterine tube B) cervix C) vagina D) ovary

Q: If a chemical were to destroy all oocytes: A) sperm would not form. B) sperm would form but have no chromosomes. C) eggs would not form. D) eggs would form but have no chromosomes.

Q: Which of the following is considered a gamete? A) embryo B) child C) oocyte D) zygote

Q: Refer to the figure below, and then answer the question that follows. Which structure, A, B, C, or D, induces formation of the neural tube?

Q: Refer to the figure below, and then answer the question that follows. Which label, A, B, or C, points to a structure formed from the archenteron during gastrulation?

Q: If you could stop diffusion of substances in fruit fly zygotes, could you stop normal development? Why or why not?

Q: Evaluate and explain the importance of positional information and morphogens in induction.

Q: What are the three phases of early embryonic development in animals, and what key events occur during each phase?

Q: Programmed cell death is also known as ________.

Q: A highly conserved sequence of 180 base pairs that controls development in many species is a/an ________.

Q: The capacity of some embryonic cells to direct the development of other embryonic cells is called ________.

Q: During gastrulation in sea urchins, which forms first, the mouth or the anus?

Q: The earliest stage of development in which cells move to particular places in the developing embryo is ________.

Q: You are a substitute teacher in a high school biology lab class on the day the students are dissecting fetal pigs. One student finds that his pig's lungs, liver, pancreas, and digestive organs are either missing or small and malformed. The student scratches his head with his clean hand and says, "What went on here?" Although there may be more than one reason, what might you propose as an explanation based on embryonic development?

Q: You are a substitute teacher in a high school biology lab class on the day the students are dissecting frogs. A particularly bright student happens to notice that the left adrenal gland is malformed in her frog. She asks if a problem in embryonic development could have caused that. Although there may be more than one reason, what might you propose as an explanation based on embryonic development?

Q: What are the three germ layers produced during gastrulation?

Q: A zygote with animal and vegetal poles demonstrates what characteristic of some animal zygotes?

Q: The morula stage is part of which phase of embryonic development?

Q: Match the following. Answers may be used more than once.A) cleavageB) organogenesisC) gastrulationNeural crest cells migrate

Q: Match the following. Answers may be used more than once.A) cleavageB) organogenesisC) gastrulationMorula develops

Q: Match the following. Answers may be used more than once.A) cleavageB) organogenesisC) gastrulationNeural tube forms

Q: Match the following. Answers may be used more than once.A) cleavageB) organogenesisC) gastrulationArchenteron develops

Q: Match the following. Answers may be used more than once.A) mesodermB) ectodermC) endodermLiver and lungs

Q: Match the following. Answers may be used more than once.A) mesodermB) ectodermC) endodermMost muscle

Q: Match the following. Answers may be used more than once.A) mesodermB) ectodermC) endodermOuter layer of skin

Q: Match the following. Answers may be used more than once.A) mesodermB) ectodermC) endodermDigestive tract lining

Q: Match the following. Answers may be used more than once.A) mesodermB) ectodermC) endodermSkeletal system

Q: Menopause and puberty are both examples of developmental changes.

Q: Different cell layers may have different cell adhesion molecules.

Q: Cells become more and more specialized as development progresses.

Q: Cell death during development will always have negative, possibly fatal, effects on normal development.

Q: Eye cells can become beak cells once they are committed.

Q: Without cell adhesion, the primitive gut probably wouldn't develop during gastrulation.

Q: Versions of homeobox genes have been found in plants and fungi.

Q: Homeobox sequences vary widely from one species to another.