BSC 111 Prin Of Bio Sci II Chapter 28
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Animals that at some stage of their lives have spinal cord running down center of their back -
CORRECT ANSWER - Vertebrates
Animals that don't have a backbone - CORRECT ANSWER - Invertebrates
Protists that most likely resemble last single-called ancestor of animals; are closest living
relatives of animals according to molecular data - CORRECT ANSWER -
Choanoflagellates
Lack of symmetry; seen in sponges that have no particular pattern for body shape - CORRECT
ANSWER - Asymmetry
Cnidarians and ctenophores exhibit it with bodies organized circularly such that any longitudinal
cut through central point produces two identical halves - CORRECT ANSWER - Radial
symmetry
Rest of animals exhibit this as adults with definite left and right halves, and only single
longitudinal cut down centerline of animal produces two equal halves - CORRECT
ANSWER - Bilateral symmetry
Accompanied bilateral symmetry; localization of brain and specialized sensory organs at anterior
end of animal - CORRECT ANSWER - Cephalization
First tissue layers that appear that give rise to organ and organ systems of complex animals -
CORRECT ANSWER - germ layers
,Embryos have only two layers, ectoderm and endoderm; cnidarians; develop tissues -
CORRECT ANSWER - Diploblastic
Develop specialized organs; embryos have three tissue layers: ectoderm, mesoderm, and
endoderm; all animals except sponges, ctenophores, cnidarians, and placozoa - CORRECT
ANSWER - Triploblastic
Mesoderm arises from cells located near embryonic blastopore that split to produce coelom;
mouth develops prior to anus; most invertebrates; spiral, determinate cleavage; mouth appears at
or near blastopore - CORRECT ANSWER - Protostomes
Anus appears at or near blastopore; anus develops prior to mouth; echinoderms and all
vertebrates; radial, indeterminate cleavage; coelom arises as pair of mesodermal pouches from
wall of primitive gut that fuse - CORRECT ANSWER - Deuterostomes
First development event after fertilization; cell division without cell growth - CORRECT
ANSWER - Cleavage
hollow sphere of cells - CORRECT ANSWER - blastula
body cavity lined with mesoderm - CORRECT ANSWER - coelom
Mesoderm cells line cavity completely - CORRECT ANSWER - True coelom
Sessile, porous bodies; Only animals to lack true tissues and to have only cellular level of
organization; only have a few cell types and lack nerve and muscle cells seen in more complex;
reproduce asexually by fragmentations or budding and sexually by releasing eggs and sperm into
central cavity and zygote developing into flagellated larva; suspension/filter feeders; bodies
made of spicules made of spongin - CORRECT ANSWER - Sponges/Porifera
Small, needle-shaped structures typically contained in endoskeleton of sponge; used to classify
sponges as bony, glass, and spongin - CORRECT ANSWER - Spicules
, Two groups of animals that have true tissues, and as embryos, they have two germ layers,
ectoderm and endoderm; radially symmetrical as adults - CORRECT ANSWER -
Ctenophores and Cnidarians
Solitary, mostly free-swimming marine invertebrates usually found in warm waters; largest of
animals propelled by beating cilia; made up of mesoglea; most capture prey by using sticky,
adhesive cells called colloblasts; have mouth and anal pores for complete digestion - CORRECT
ANSWER - Comb jellies / Ctenophora
Transparent, jellylike substance that makes up body of ctenophores - CORRECT
ANSWER - Mesoglea
Organisms capable of producing their own light - CORRECT ANSWER - Bioluminescent
Tubular or bell-shaped animals that reside mainly in shallow coastal waters through some
freshwater, brackish, and oceanic forms exist; have gastrovascular cavity; reproduce sexually or
asexually; includes hydras, jellyfish, sea anemones, and corals - CORRECT ANSWER -
Cnidarians (nettles)
Presence of specialized stinging cells called cnidocytes - CORRECT ANSWER - Cnidaria
Fluid-filled, stinging capsule that contains long, spirally coiled, hollow thread; discharged when
trigger of cnidocyte is pressed - CORRECT ANSWER - Nematocyst
Internal cavity filled with fluid; that functions in digestion of food and circulation of nutrients -
CORRECT ANSWER - Gastrovascular cavity
Offers some resistance to contraction of muscle but permits flexibility - CORRECT
ANSWER - Hydrostatic skeleton
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Animals that at some stage of their lives have spinal cord running down center of their back -
CORRECT ANSWER - Vertebrates
Animals that don't have a backbone - CORRECT ANSWER - Invertebrates
Protists that most likely resemble last single-called ancestor of animals; are closest living
relatives of animals according to molecular data - CORRECT ANSWER -
Choanoflagellates
Lack of symmetry; seen in sponges that have no particular pattern for body shape - CORRECT
ANSWER - Asymmetry
Cnidarians and ctenophores exhibit it with bodies organized circularly such that any longitudinal
cut through central point produces two identical halves - CORRECT ANSWER - Radial
symmetry
Rest of animals exhibit this as adults with definite left and right halves, and only single
longitudinal cut down centerline of animal produces two equal halves - CORRECT
ANSWER - Bilateral symmetry
Accompanied bilateral symmetry; localization of brain and specialized sensory organs at anterior
end of animal - CORRECT ANSWER - Cephalization
First tissue layers that appear that give rise to organ and organ systems of complex animals -
CORRECT ANSWER - germ layers
,Embryos have only two layers, ectoderm and endoderm; cnidarians; develop tissues -
CORRECT ANSWER - Diploblastic
Develop specialized organs; embryos have three tissue layers: ectoderm, mesoderm, and
endoderm; all animals except sponges, ctenophores, cnidarians, and placozoa - CORRECT
ANSWER - Triploblastic
Mesoderm arises from cells located near embryonic blastopore that split to produce coelom;
mouth develops prior to anus; most invertebrates; spiral, determinate cleavage; mouth appears at
or near blastopore - CORRECT ANSWER - Protostomes
Anus appears at or near blastopore; anus develops prior to mouth; echinoderms and all
vertebrates; radial, indeterminate cleavage; coelom arises as pair of mesodermal pouches from
wall of primitive gut that fuse - CORRECT ANSWER - Deuterostomes
First development event after fertilization; cell division without cell growth - CORRECT
ANSWER - Cleavage
hollow sphere of cells - CORRECT ANSWER - blastula
body cavity lined with mesoderm - CORRECT ANSWER - coelom
Mesoderm cells line cavity completely - CORRECT ANSWER - True coelom
Sessile, porous bodies; Only animals to lack true tissues and to have only cellular level of
organization; only have a few cell types and lack nerve and muscle cells seen in more complex;
reproduce asexually by fragmentations or budding and sexually by releasing eggs and sperm into
central cavity and zygote developing into flagellated larva; suspension/filter feeders; bodies
made of spicules made of spongin - CORRECT ANSWER - Sponges/Porifera
Small, needle-shaped structures typically contained in endoskeleton of sponge; used to classify
sponges as bony, glass, and spongin - CORRECT ANSWER - Spicules
, Two groups of animals that have true tissues, and as embryos, they have two germ layers,
ectoderm and endoderm; radially symmetrical as adults - CORRECT ANSWER -
Ctenophores and Cnidarians
Solitary, mostly free-swimming marine invertebrates usually found in warm waters; largest of
animals propelled by beating cilia; made up of mesoglea; most capture prey by using sticky,
adhesive cells called colloblasts; have mouth and anal pores for complete digestion - CORRECT
ANSWER - Comb jellies / Ctenophora
Transparent, jellylike substance that makes up body of ctenophores - CORRECT
ANSWER - Mesoglea
Organisms capable of producing their own light - CORRECT ANSWER - Bioluminescent
Tubular or bell-shaped animals that reside mainly in shallow coastal waters through some
freshwater, brackish, and oceanic forms exist; have gastrovascular cavity; reproduce sexually or
asexually; includes hydras, jellyfish, sea anemones, and corals - CORRECT ANSWER -
Cnidarians (nettles)
Presence of specialized stinging cells called cnidocytes - CORRECT ANSWER - Cnidaria
Fluid-filled, stinging capsule that contains long, spirally coiled, hollow thread; discharged when
trigger of cnidocyte is pressed - CORRECT ANSWER - Nematocyst
Internal cavity filled with fluid; that functions in digestion of food and circulation of nutrients -
CORRECT ANSWER - Gastrovascular cavity
Offers some resistance to contraction of muscle but permits flexibility - CORRECT
ANSWER - Hydrostatic skeleton
