Campbell Biology Chapter 32 / Actual Test Questions with Detailed
Campbell Biology Chapter 32
VerifiedStudyAnswers / Already Graded A / .
online at https://quizlet.com/_9nhab
1. animals multicellular, heterotrophic eukaryotes with tissues developed from embryonic
layers
2. collagen the most abundant structural protein that helds together the animal cells
3. cleavage The process of cytokinesis in animal cells, characterized by pinching of the plasma
membrane; specifically, the succession of rapid cell divisions without growth dur-
ing early embryonic development that converts the zygote into a ball of cells.
4. blastula The hollow ball of cells marking the end stage of cleavage during early embryonic
development
5. gastrulation developmental process in which three distinct cell layers form in an embryo: the
endoderm, mesoderm, and ectoderm
6. gastrula a stage of embryonic development characterized by the differentiation of the
cells into the ectoderm and endoderm germ layers and by the formation of the
archenteron
7. larva A free-living, sexually immature form in some animal life cycles that may differ from
the adult in morphology, nutrition, and habitat.
8. metamorphosis the marked and rapid transformation of a larva into a juvenile, which resembles
the adult but is not yet sexually mature.
9. Hox genes Series of genes that controls the differentiation of cells and tissues in an embryo
10. choanoflagellets closest living relatives to the animalia
11. Ediacaran biota An early group of soft-bodied, multicellular eukaryotes known from fossils that
range in age from 565 million to 550 million years old.
12. Cambrian explo-
sion
1/5
, Campbell Biology Chapter 32
Study online at https://quizlet.com/_9nhab
A burst of evolutionary origins when most of the major body plans of animals
appeared in a relatively brief time in geologic history; recorded in the fossil record
about 535 to 525 million years ago.
13. radial symmetry body plan in which body parts repeat around the center of the body; characteristic
of sea anemones and sea stars
14. bilateral symme- body plan in which only a single, imaginary line can divide the body into two equal
try halves; characteristic of worms, arthropods, and chordates
15. dorsal side top side, back of an animal - the spine side, away from the abdomen
16. ventral side The underside, belly, or the lower body surface
17. anterior end the end of an animal that contains its head
18. posterior end the end of an animal that contains its tail
19. cephalization concentration of sense organs and nerve cells at the front of an animal's body
(head and brain)
20. sessile describes an organism that remains attached to a surface for its entire life - radial
animals
21. planktonic drifting passively with currents - radial animals
22. Germ layers ectoderm, endoderm, mesoderm
23. ectoderm The outermost of the three primary germ layers in animal embryos; gives rise to
the outer covering and, in some phyla, the nervous system, inner ear, and lens of
the eye
24. endoderm The innermost of the three primary germ layers in animal embryos; lines the
archenteron and gives rise to the liver, pancreas, lungs, and the lining of the
digestive tract
2/5
Campbell Biology Chapter 32
VerifiedStudyAnswers / Already Graded A / .
online at https://quizlet.com/_9nhab
1. animals multicellular, heterotrophic eukaryotes with tissues developed from embryonic
layers
2. collagen the most abundant structural protein that helds together the animal cells
3. cleavage The process of cytokinesis in animal cells, characterized by pinching of the plasma
membrane; specifically, the succession of rapid cell divisions without growth dur-
ing early embryonic development that converts the zygote into a ball of cells.
4. blastula The hollow ball of cells marking the end stage of cleavage during early embryonic
development
5. gastrulation developmental process in which three distinct cell layers form in an embryo: the
endoderm, mesoderm, and ectoderm
6. gastrula a stage of embryonic development characterized by the differentiation of the
cells into the ectoderm and endoderm germ layers and by the formation of the
archenteron
7. larva A free-living, sexually immature form in some animal life cycles that may differ from
the adult in morphology, nutrition, and habitat.
8. metamorphosis the marked and rapid transformation of a larva into a juvenile, which resembles
the adult but is not yet sexually mature.
9. Hox genes Series of genes that controls the differentiation of cells and tissues in an embryo
10. choanoflagellets closest living relatives to the animalia
11. Ediacaran biota An early group of soft-bodied, multicellular eukaryotes known from fossils that
range in age from 565 million to 550 million years old.
12. Cambrian explo-
sion
1/5
, Campbell Biology Chapter 32
Study online at https://quizlet.com/_9nhab
A burst of evolutionary origins when most of the major body plans of animals
appeared in a relatively brief time in geologic history; recorded in the fossil record
about 535 to 525 million years ago.
13. radial symmetry body plan in which body parts repeat around the center of the body; characteristic
of sea anemones and sea stars
14. bilateral symme- body plan in which only a single, imaginary line can divide the body into two equal
try halves; characteristic of worms, arthropods, and chordates
15. dorsal side top side, back of an animal - the spine side, away from the abdomen
16. ventral side The underside, belly, or the lower body surface
17. anterior end the end of an animal that contains its head
18. posterior end the end of an animal that contains its tail
19. cephalization concentration of sense organs and nerve cells at the front of an animal's body
(head and brain)
20. sessile describes an organism that remains attached to a surface for its entire life - radial
animals
21. planktonic drifting passively with currents - radial animals
22. Germ layers ectoderm, endoderm, mesoderm
23. ectoderm The outermost of the three primary germ layers in animal embryos; gives rise to
the outer covering and, in some phyla, the nervous system, inner ear, and lens of
the eye
24. endoderm The innermost of the three primary germ layers in animal embryos; lines the
archenteron and gives rise to the liver, pancreas, lungs, and the lining of the
digestive tract
2/5
