UH MANOA BIO 172 EXAM 2 WITH
100% CORRECT ANSWERS 2026
Animal Characteristics correct answer multicellular,
eukaryotes, heterotrophs, bodies are held together by structures
like collagen, lack cell walls
Collagen correct answer structural protein found in the skin
and connective tissue. flexible, highly tensile and resiliant
Skin correct answer dense, irregular arrangement
Ligament correct answer attaches bone to bone, arranged in
sheets
Tendon correct answer attaches muscle to bone, cable-like
arrangement
Other characteristics correct answer most animals reproduce
sexually, diploid stage is dominant and the zygote undergoes
rapid cell division called cleavage
Tissues correct answer groups of similar cells that perform a
specific function in an organism. isolated from other tissues by
membranous layers
,Germ layers correct answer three main layers that form the
various tissues and organs of an animal body.
Blastula correct answer the hollow ball of cells marking the
end stage of cleavage during early embryonic development
Gastrulation 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.
Endoderm correct answer the inner germ layer that develops
into the lining of the digestive and respiratory systems
Archeteron correct answer the internal pouch formed in
gastrulation
Ectoderm correct answer outermost germ layer; produces
sense organs, nerves, and outer layer of skin
Diploblast correct answer an animal that develops from two
embryonic germ layers
Triploblast correct answer animal that develops from three
germ layers
Bilaterians correct answer -have bilateral symmetry -all
multicellular animals but sponges and cnidarians
,Cephalization correct answer organization of senses and
movement toward the head region
Larval stage correct answer sexually immature form that is
anatomically distinct from the adult and goes through
metamorphosis
Juvenile correct answer resembles an adult but isn't sexually
mature
Sacculina correct answer a parasite barnacle that injects cells
into crustaceans. co-evolved with the crustaceans
Animal Diversity from hypothesized ancestor correct answer
675 and 800 million years ago
Cambrian Explosion correct answer (535 to 525 million years
ago) marks the earliest fossil appearance of many major groups
of living animals
Cambrian Explosion Hypotheses correct answer new predator-
prey relationships, rise in atmospheric oxygen levels
(cyanobacteria and plants), evolution of Hox gene complex
Hox Gene Complex correct answer a sequence of DNA that
regulates the expression of genes that control the development of
body structures and therefore morphologies
Bilaterian Groups correct answer 1. Deuterostomes
, 2. Lophotrochozoa
3. Ecdysozoa
Coelom correct answer body cavity structure
Placozoa correct answer simplest animal, smallest genome
with 11,500 genes, 4 cell types, no symmetry organs muscles or
nervous system
Metazoans correct answer all animals
Phylum Porifera correct answer aka sponges; means animal
that contains holes; are sessile feeders (stuck to the ground,
eating what comes near them); body symmetry: asymmetric eg.
yellow tube sponge
Porifera Movement correct answer move using flagella-bearing
collar cells which create water currents through the body which is
sometimes supported by spicules
Spicules correct answer Calcium or silica structures that
support sponge body
Amoebocyte correct answer within the body wall of a sponge,
a specialized cell that crawls about and delivers nutrients from
the choanocytes to the rest of the body cells
Choanocytes correct answer flagellated collar cells, generate a
water current through the sponge and ingest suspended food
100% CORRECT ANSWERS 2026
Animal Characteristics correct answer multicellular,
eukaryotes, heterotrophs, bodies are held together by structures
like collagen, lack cell walls
Collagen correct answer structural protein found in the skin
and connective tissue. flexible, highly tensile and resiliant
Skin correct answer dense, irregular arrangement
Ligament correct answer attaches bone to bone, arranged in
sheets
Tendon correct answer attaches muscle to bone, cable-like
arrangement
Other characteristics correct answer most animals reproduce
sexually, diploid stage is dominant and the zygote undergoes
rapid cell division called cleavage
Tissues correct answer groups of similar cells that perform a
specific function in an organism. isolated from other tissues by
membranous layers
,Germ layers correct answer three main layers that form the
various tissues and organs of an animal body.
Blastula correct answer the hollow ball of cells marking the
end stage of cleavage during early embryonic development
Gastrulation 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.
Endoderm correct answer the inner germ layer that develops
into the lining of the digestive and respiratory systems
Archeteron correct answer the internal pouch formed in
gastrulation
Ectoderm correct answer outermost germ layer; produces
sense organs, nerves, and outer layer of skin
Diploblast correct answer an animal that develops from two
embryonic germ layers
Triploblast correct answer animal that develops from three
germ layers
Bilaterians correct answer -have bilateral symmetry -all
multicellular animals but sponges and cnidarians
,Cephalization correct answer organization of senses and
movement toward the head region
Larval stage correct answer sexually immature form that is
anatomically distinct from the adult and goes through
metamorphosis
Juvenile correct answer resembles an adult but isn't sexually
mature
Sacculina correct answer a parasite barnacle that injects cells
into crustaceans. co-evolved with the crustaceans
Animal Diversity from hypothesized ancestor correct answer
675 and 800 million years ago
Cambrian Explosion correct answer (535 to 525 million years
ago) marks the earliest fossil appearance of many major groups
of living animals
Cambrian Explosion Hypotheses correct answer new predator-
prey relationships, rise in atmospheric oxygen levels
(cyanobacteria and plants), evolution of Hox gene complex
Hox Gene Complex correct answer a sequence of DNA that
regulates the expression of genes that control the development of
body structures and therefore morphologies
Bilaterian Groups correct answer 1. Deuterostomes
, 2. Lophotrochozoa
3. Ecdysozoa
Coelom correct answer body cavity structure
Placozoa correct answer simplest animal, smallest genome
with 11,500 genes, 4 cell types, no symmetry organs muscles or
nervous system
Metazoans correct answer all animals
Phylum Porifera correct answer aka sponges; means animal
that contains holes; are sessile feeders (stuck to the ground,
eating what comes near them); body symmetry: asymmetric eg.
yellow tube sponge
Porifera Movement correct answer move using flagella-bearing
collar cells which create water currents through the body which is
sometimes supported by spicules
Spicules correct answer Calcium or silica structures that
support sponge body
Amoebocyte correct answer within the body wall of a sponge,
a specialized cell that crawls about and delivers nutrients from
the choanocytes to the rest of the body cells
Choanocytes correct answer flagellated collar cells, generate a
water current through the sponge and ingest suspended food
