교과서 질문
One of the characteristics unique to animals is
a. Gastrulation
b. Multicellularity
c. Sexual reproduction
d. Flagellated sperm
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검증된 단계별 안내
One of the characteristics unique to animals is
a. Gastrulation
b. Multicellularity
c. Sexual reproduction
d. Flagellated sperm
The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of
a. A body cavity
b. A complete digestive tract
c. Mesoderm
d. Tissues
Which of the following was probably an important factor in bringing about the Cambrian explosion?
a. The movement of animals onto land
b. An increase in the concentration of atmospheric nitrogen
c. The emergence of predator-prey relationships
d. The origin of bilaterian animals