Morula is a stage of
embryonic development in
animals, including the 16-cell phase, the 32-cell phase, and the 64-cell phase. The morula is produced by
embryonic cleavage[?], the rapid
cell division of the
zygote with virtually no growth. The morula is a solid ball; after the 64-cell phase, it develops into a hollow ball, the
blastula.
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