Zoology Exam Questions and Answers
Graded A+
radial symmetry - Correct answer-body plan in which any number of imaginary
planes drawn through the center of the body could divide it into equal halves
sessile - Correct answer-Describes an organism that remains attached to a surface
for its entire life and does not move
bilateral symmetry - Correct answer-Body plan in which only a single, imaginary
line can divide the body into two equal halves.
morula - Correct answer-A solid ball of cells that makes up an embryo; in humans,
this stage occurs within four days of fertilization.
blastula - Correct answer-A hollow ball of cells that marks the end of the cleavage
stage during early embryonic development in animals.
blastocoel - Correct answer-the fluid-filled cavity inside a blastula
gastrula - Correct answer-In animal development, a series of cell and tissue
movements in which the blastula-stage embryo folds inward, producing a three-
layered embryo, the gastrula.
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, blastopore - Correct answer-The opening of the archenteron in the gastrula that
develops into the mouth in protostomes and the anus in deuterostomes
archenteron - Correct answer-The central cavity in the gastrula stage of
embryological development; it is lined by endoderm and ultimately gives rise to
the adult digestive tract.
mesoderm - Correct answer-which germ layer gives rise to muscle (smooth and
striated), bone, cartilage, connective tissue, adipose tissue, circulatory system,
lymphatic system, dermis, genitourinary system, serous membranes, and
notochord.
endoderm - Correct answer-Which germ layer gives rise to the stomach, the colon,
the liver, the pancreas, the urinary bladder, the epithelial parts of trachea, the lungs,
the pharynx, the thyroid, the parathyroid, and the intestines.
ectoderm - Correct answer-The surface ___________ develops into: epidermis,
hair, nails, lens of the eye, sebaceous glands, cornea, tooth enamel, the epithelium
of the mouth and nose.
The neural crest of the _________ develops into: peripheral nervous system,
adrenal medulla, melanocytes, facial cartilage, dentin of teeth.
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Graded A+
radial symmetry - Correct answer-body plan in which any number of imaginary
planes drawn through the center of the body could divide it into equal halves
sessile - Correct answer-Describes an organism that remains attached to a surface
for its entire life and does not move
bilateral symmetry - Correct answer-Body plan in which only a single, imaginary
line can divide the body into two equal halves.
morula - Correct answer-A solid ball of cells that makes up an embryo; in humans,
this stage occurs within four days of fertilization.
blastula - Correct answer-A hollow ball of cells that marks the end of the cleavage
stage during early embryonic development in animals.
blastocoel - Correct answer-the fluid-filled cavity inside a blastula
gastrula - Correct answer-In animal development, a series of cell and tissue
movements in which the blastula-stage embryo folds inward, producing a three-
layered embryo, the gastrula.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, blastopore - Correct answer-The opening of the archenteron in the gastrula that
develops into the mouth in protostomes and the anus in deuterostomes
archenteron - Correct answer-The central cavity in the gastrula stage of
embryological development; it is lined by endoderm and ultimately gives rise to
the adult digestive tract.
mesoderm - Correct answer-which germ layer gives rise to muscle (smooth and
striated), bone, cartilage, connective tissue, adipose tissue, circulatory system,
lymphatic system, dermis, genitourinary system, serous membranes, and
notochord.
endoderm - Correct answer-Which germ layer gives rise to the stomach, the colon,
the liver, the pancreas, the urinary bladder, the epithelial parts of trachea, the lungs,
the pharynx, the thyroid, the parathyroid, and the intestines.
ectoderm - Correct answer-The surface ___________ develops into: epidermis,
hair, nails, lens of the eye, sebaceous glands, cornea, tooth enamel, the epithelium
of the mouth and nose.
The neural crest of the _________ develops into: peripheral nervous system,
adrenal medulla, melanocytes, facial cartilage, dentin of teeth.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
