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Stem cells (unspecialized cells) that develop into bone cells have undergone which type of process?


A) involution
B) embryonic development
C) cellular differentiation
D) cellular respiration

E) B) and C)
F) A) and D)

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A certain drug has a side-effect of disrupting levels of luteinizing hormone (LH) .Which patients should be advised that this drug could affect their fertility?


A) Men
B) Women
C) Men and women
D) Neither -- it would only disrupt late fetal development.

E) A) and B)
F) C) and D)

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A mutation in mice leads to overgrowth of the Sertoli cells,so they span across the diameter of the seminiferous tubules.What phenotype would you expect to see?


A) infertility due to lack of mature oocytes
B) overproduction of sperm,so they clog the bulbourethral gland
C) overproduction of testosterone
D) infertility due to lack of mature sperm entering the epididymis

E) A) and D)
F) B) and D)

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The cortical reaction causes


A) the vitelline layer to harden.
B) the embryo to embed into the uterus.
C) egg membrane depolarization.
D) the sperm to bind to the egg membrane.
E) follicle maturation.

F) B) and C)
G) A) and B)

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One type of illegal doping in sports is the abuse of anabolic steroids such as testosterone.Doctors measure the testosterone (T) to LH ratio in athletes' urine to detect such doping.Why is this an effective indicator?


A) Testosterone upregulates LH,so the doping athlete will have an unusually low T/LH ratio.
B) LH downregulates testosterone,so the doping athlete will have an unusually low T/LH ratio.
C) LH has negative feedback onto testosterone,so the doping athlete will have an unusually high T/LH ratio.
D) Testosterone has negative feedback onto LH production,so the doping athlete will have an unusually high T/LH ratio.

E) B) and D)
F) None of the above

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What stage of development involves cell division without cell growth?


A) fertilization
B) cleavage
C) neurulation
D) gastrulation
E) organogenesis

F) A) and D)
G) A) and C)

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Place the events of parturition in the correct order. (1) Stretch-sensitive neurons send signals to the hypothalamus. (2) Oxytocin receptors increase in the uterus. (3) Prostaglandin levels increase. (4) Estradiol levels increase. (5) Oxytocin levels increase. (6) Uterine muscles start to contract.


A) 1,2,4,5,3,6
B) 4,2,1,5,6,3
C) 5,2,4,1,3,6
D) 1,6,4,2,5,3
E) 4,3,1,2,5,6

F) All of the above
G) A) and B)

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Mesoderm gives rise to


A) epidermis.
B) respiratory tract.
C) digestive tract.
D) skeletal muscle.
E) peripheral nervous system.

F) A) and E)
G) A) and D)

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What are the three glands that produce the liquid portion of semen?


A) prostate,seminal vesicles,bulbourethral
B) hypothalamus,prostate,Leydig
C) Leydig,prostate,bulbourethral
D) seminal vesicles,hypothalamus,bulbourethral
E) seminal vesicle,Leydig,hypothalamus

F) C) and E)
G) A) and B)

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Why don't chickens menstruate?


A) It has been bred out of them.
B) The early embryo receives nutrients from the egg yolk.
C) The corpus luteum of a chicken is much smaller and passes without notice.
D) The eggshell serves the same purpose as the endometrium.

E) B) and C)
F) A) and B)

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The posterior end of the neural tube will develop into the brain.

A) True
B) False

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In chordates,which mesoderm structure forms during gastrulation and provides structural rigidity along the dorsal anterioposterior axis of the embryo?


A) archenteron
B) neural tube
C) notochord
D) epidermis
E) intestinal tract

F) A) and E)
G) B) and C)

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Which one of the structures below does NOT develop during neurulation?


A) cells that form pigment
B) the central nervous system
C) the neural crest
D) the archenteron
E) somites

F) C) and D)
G) B) and E)

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Place the following events of the acrosomal reaction in the correct chronological order. (1) The acrosome releases hydrolytic enzymes. (2) Sperm-binding proteins on the membrane bind the sperm. (3) Sperm nucleus enters the egg. (4) Sperm and egg plasma membranes fuse. (5) Sperm contacts the egg's jelly coat.


A) 5,1,2,4,3
B) 1,5,4,3,2
C) 1,2,4,3,5
D) 5,2,4,3,1
E) 3,5,2,1,4

F) A) and B)
G) A) and C)

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Erection occurs when


A) the spongy erectile tissue of the penis becomes engorged with blood.
B) the veins flowing out of the penis vasoconstrict.
C) the arteries of the penis vasodilate.
D) nitric oxide is releaseD.
E) All of these events occur to promote an erection.

F) B) and D)
G) D) and E)

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What allows fetal hemoglobin to remove oxygen from maternal hemoglobin?


A) Fetal hemoglobin has an extra heme group.
B) Oxygen is more soluble in fetal blood than maternal blood.
C) Fetal hemoglobin has a higher affinity for oxygen than does maternal hemoglobin.
D) Fetal blood contains twice as many hemoglobin molecules than maternal blooD.
E) Fetal hemoglobin molecules are much larger than maternal hemoglobin molecules.

F) B) and D)
G) B) and C)

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What would happen if the cortical reaction proceeded before the acrosomal reaction was complete?


A) Fertilization would not occur.
B) This is the normal situation.
C) Multiple sperm would fertilize the egg.
D) Twins may form.

E) A) and B)
F) A) and C)

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Paland and Lynch showed that sexual populations have fewer deleterious mutations than asexual populations.What hypothesis do these results support?


A) sexual reproduction prevents fertilization with gametes carrying alleles with deleterious alleles.
B) sexual reproduction produces fewer random mutations than asexual reproduction.
C) asexual reproduction is associated with lower genetic diversity,resulting in the accumulation of highly deleterious mutations.
D) in sexual reproduction,the reassorting of alleles allows for the elimination of more detrimental alleles than in asexual reproduction.
E) sexual strains are associated with higher genetic diversity and thus accumulate more beneficial mutations than asexual strains.

F) C) and D)
G) B) and E)

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Neural crest cells at the dorsal surface of the neural tube


A) form the notochord.
B) form the overlying ectoderm.
C) migrate to many different regions of the body.
D) differentiate into the brain.
E) control the segmentation of somatic mesoderm.

F) A) and D)
G) All of the above

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The sharp peak of estradiol secretion during the ovarian cycle


A) inhibits the secretion of LH and FSH.
B) stimulates the secretion of LH and ovulation.
C) stimulates growth of the uterine lining.
D) stimulates completion of meiosis I.
E) inhibits progesterone production.

F) A) and D)
G) B) and E)

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