A) the acrosomal reaction and the formation of egg white.
B) the cortical reaction and the formation of yolk protein.
C) the jelly coat of the egg and the vitelline membrane.
D) membrane depolarization and the cortical reaction.
E) inactivation of the sperm acrosome.
Correct Answer
verified
Multiple Choice
A) cleavage would not occur in the zygote.
B) embryonic germ layers would not form.
C) fertilization would be blocked.
D) the blastula would not be formed.
E) the blastopore would form above the gray crescent in the animal pole.
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Multiple Choice
A) cleavage → blastula → gastrula → morula
B) cleavage → gastrula → morula → blastula
C) cleavage → morula → blastula → gastrula
D) gastrula → morula → blastula → cleavage
E) morula → cleavage → gastrula → blastula
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Multiple Choice
A) extraembryonic membranes
B) yolk
C) cleavage
D) gastrulation
E) development of the brain from ectoderm
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verified
Multiple Choice
A) a large supply of yolk.
B) an aqueous environment.
C) extraembryonic membranes.
D) an amnion.
E) a primitive streak.
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verified
Multiple Choice
A) mitosis.
B) membrane depolarization.
C) apoptosis.
D) vitellogenesis.
E) acrosomal reaction.
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Multiple Choice
A) located near the animal pole.
B) located near the vegetal pole.
C) found within the cleavage furrow.
D) found within the blastocoels.
E) distributed equally throughout the embryo.
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verified
Multiple Choice
A) of the heterogeneous distribution of cytoplasmic determinants in unfertilized eggs.
B) of interactions between extraembryonic cells and the zygote nucleus.
C) of convergent extension.
D) early blastomeres can form a complete embryo if isolated.
E) the gray crescent divides the dorsal-ventral axis into new cells.
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verified
Multiple Choice
A) nervous system.
B) liver.
C) pancreas.
D) heart.
E) kidneys.
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Multiple Choice
A) formation of a fertilization envelope.
B) production of a fast block to polyspermy.
C) release of hydrolytic enzymes from the sperm cell.
D) generation of a nerve-like impulse by the egg cell.
E) fusion of egg and sperm nuclei.
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verified
Multiple Choice
A) 5 seconds after fertilization.
B) 30 minutes after fertilization.
C) 90 minutes after fertilization.
D) 4 hours after fertilization.
E) 24 hours after fertilization.
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verified
Multiple Choice
A) an embryonic cell that is much smaller than the ovum.
B) an embryonic structure that includes a fluid-filled cavity.
C) that part of the acrosome that opens the egg's membrane.
D) a component of the zona pellucida.
E) a cell that contains a (degenerating) second polar body.
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verified
Multiple Choice
A) endoderm.
B) mesoderm.
C) ectoderm.
D) neural crest.
E) hypoblast.
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Multiple Choice
A) skip the mitosis phase of the cell cycle.
B) skip the S phase of the cell cycle.
C) skip the G₁ and G₂ phases of the cell cycle.
D) rapidly increase the volume and mass of the embryo.
E) skip the cytokinesis phase of the cell cycle.
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verified
Multiple Choice
A) opens the egg's nuclear membrane to allow haploid sperm DNA to enter.
B) hardens to form a protective cover.
C) secretes hormones that enhance steroidogenesis by the ovary.
D) reduces the loss of water from the egg and prevents desiccation.
E) provides most of the nutrients used by the zygote.
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verified
Multiple Choice
A) light and temperature.
B) salt gradients and membrane potentials.
C) gravity and pH.
D) moisture and mucus.
E) location of sperm penetration and cortical reaction.
Correct Answer
verified
Multiple Choice
A) nuclei in a zygote.
B) nuclei in an early embryo.
C) nuclei in an egg prior to fertilization.
D) cytoplasmic determinants in a newly formed zygote.
E) cytoplasmic determinants in a baby just prior to birth.
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verified
Multiple Choice
A) germ layers.
B) morula.
C) blastopore.
D) gastrulation.
E) invagination.
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verified
Multiple Choice
A) the lip of the blastopore in the frog.
B) the archenteron in a frog.
C) polar bodies in a sea urchin.
D) the notochord in a mammal.
E) neural crest cells in a mammal.
Correct Answer
verified
Multiple Choice
A) increases as the number of the blastomeres decreases.
B) increases as the number of the blastomeres increases.
C) decreases as the number of the blastomeres increases.
D) decreases as the number of the blastomeres decreases.
E) increases as the number of the blastomeres stays the same.
Correct Answer
verified
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