CORRECT ANSWERS
Cambrian Explosion/Period - ✔✔ the most rapid evolution of new animal phyla and animal
diversity in Earth's history about 542-488 MYA
Which of the following is not typical of most animals?
A) Specialized tissues
B) a stage of development called gastrulation
C) possession of hox genes
D) alternation of generations between diploid and haploid lifestages
E) food obtained via heterotrophy - ✔✔ D) Alternation of generations between diploid and
haploid lifestages
Hox Genes - ✔✔ Responsible for the general body pattern of most animals
Gastrulation - ✔✔ results in the formation of the primitive gut (archenteron) or digestive cavity
and the formation of the embryonic layers.
Organogenesis - ✔✔ formation of organs
Which of the following is true of the animal phylogenetic tree?
,A) fossils provide the best source of information for determining the animal phylogenetic tree
B) major accepted clades of the animal phylogeny have remained constant over the past 50 years
C) Future DNA evidence is likely to demonstrate that the Bilateria is the most primitive animal
clade
D) Eumetazoans include more species than Metazoans
E) As more DNA is sequenced and analyzed from more animals, future changes to major
surviving clades of the animal phylogenetic tree become less likely. - ✔✔ E) As more DNA is
sequenced and analyzed from more animals, future changes to major surviving clades of the
animal phylogenetic tree become less likely
Which of the following is not true of the coelom?
A) it may be present in triploblastic organisms
B) it is a cavity the houses internal organs
C) it is derived from mesoderm
D) it is present in all animals
E) it usually contain fluids - ✔✔ D) it is present in all animals
Triploblastic - ✔✔ Having 3 embryonic layers (endoderm, mesoderm, and ectoderm)
Diploblastic - ✔✔ Having 2 embryonic layers (endoderm and ectoderm).
Which of the following does not play a major role in Earth's post-Cambrian animal evolution?
,A) evolution among plants
B) meteor strikes
C) Change in distance between the Earth and the sun
D) shift in Earth's geography
E) cataclysmic volcanic eruptions - ✔✔ C) change in distance between the Earth and the sun
Which of the following is not found in Cnidarians?
A) planula larvae
B)medusae
C)cnidocytes
D)mesoderm
E)polyps - ✔✔ D) mesoderm
planula larvae - ✔✔ larvae of various cnidarians
medusae - ✔✔ free-floating aquatic animals with a structure similar to a jellyfish
cnidocytes - ✔✔ stinging cells
Gemmules - ✔✔ Environmentally resistant structures produced by adult sponges
Which of the following is not a component of a sponge?
, A) osculum
B)mesohyl
C)endoderm
D)amoebocytes
E)ostia - ✔✔ C) endoderm
osculum - ✔✔ A large opening on a sponge through which filtered water is expelled
mesohyl - ✔✔ gelatinous matrix within a sponge
Which of the following is not a component of sponge reproduction?
A) release of eggs into the water column
B)transformation of choanocytes into sperm cells
C) budding
D) gemmules
E)fragmentation - ✔✔ A) release of eggs into the water column
Class Anthozoa
A) are polyploid
B) have nematocysts