1.
The study of animal development from the fertilized egg to the formation of all major organ systems is calledA) comparative anatomy B) embryology C) entomology D) molecular biology 2.
Lysins are released from the ___________ and dissolve the gel coat of an egg during fertilization.A) vitelline layer B) mitochondria C) acrosome D) microvilli 3.
All of the following are a part of membrane and cortical events associated with egg activation except one. Select the exception.A) Microvilli from the egg plasma membrane wrap around a sperm cell. B) A fertilization membrane forms. C) The mitotic spindle forms. D) The cortical layer thickens, and rotational and sliding movements of the outer egg cytoplasm begin. 4.
Echinoderm embryology is commonly studied becauseA) they are the organisms most closely related to humans. B) they are a deuterostome, like humans, and are easily studied. C) only their embryology can be easily studied in the laboratory. D) their embryological changes are identical to humans. 5.
______ forms the inner lining of the digestive cavity of an embryo.A) Ectoderm B) Mesoderm C) Endoderm D) Blastoderm 6.
_______ forms muscle, blood, skeletal elements and other connective tissues.A) Ectoderm B) Mesoderm C) Endoderm D) Blastoderm 7.
A stage of echinoderm embryology consisting of a hollow ball of cells is called theA) morula. B) blastula. C) gastrula. D) archenteron. 8.
Invagination of cells in the vegetal half of the echinoderm embryo occurs during a process calledA) gastrulation. B) neurulation. C) morphogenesis. D) epiboly. 9.
All of the following are structures that characterize chordates except one. Select the exception.A) dorsal tubular nervous system B) open circulatory system C) notochord D) pharyngeal slits or pouches 10.
Gastrulation in an amphibian embryo occurs as superficial cells begin to roll over the dorsal lip of the blastopore in a process calledA) epiboly. B) morphogenesis. C) neurulation. D) involution. 11.
All of the following are formed during gastrulation in an amphibian embryo except one. Select the exception.A) yolk plug B) archenteron C) blastopore D) blastocoel 12.
In the amphibian embryo, the notochord and mesoderm form fromA) ectoderm. B) endoderm. C) chordamesoderm. D) hypoblast. 13.
Early cleavages in the zygote of a bird result in the formation of theA) blastoderm. B) Henson's node. C) amnion. D) chorion. 14.
An inward migration of epiblast cells of the bird embryo results in the formation of mesoderm. This migration occurs along a linear invagination called theA) dorsal lip of the blastopore. B) primitive streak. C) chordamesoderm. D) allantois. 15.
The extraembryonic membranes of amniotes include all of the following except one. Select the exception.A) amnion B) somite C) chorion D) allantois 16.
The fusion of the sperm nucleus and the egg nucleus is the beginning of a series of biochemical changes in the egg that ensures the completion of fertilization and initiates embryonic development. These changes are called egg activation.A) True B) False 17.
Most mRNA used during protein synthesis that occurs in early development is deposited in the egg by the mother.A) True B) False 18.
Cleavages produce blastomeres, which divide synchronously for a short time.A) True B) False 19.
In an echinoderm embryo, the coelom forms as a result of splitting solid blocks of mesoderm.A) True B) False 20.
Gastrulation of the amphibian embryo results in a spreading and thinning of ectodermal cells toward the blastopore. This process is called epiboly.A) True B) False 21.
The extraembryonic membrane that encloses a bird embryo in a fluid-filled sac is the amnion.A) True B) False 22.
The extraembryonic membrane that encloses embryonic wastes of a bird is the chorion.A) True B) False 23.
After gastrulation of a bird embryo, the embryo lifts off the yolk but remains connected to the yolk through a yolk stalk. Blood vessels develop in the yolk stalk that carry nutrients from the yolk to the embryo.A) True B) False 24.
The amnion and the chorion of a bird embryo become highly vascular and function in gas exchange.A) True B) False 25.
Frog eggs have a pigmented side, and this dark side oriented upwards has an adaptive value.A) True B) False