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8 Cards in this Set

  • Front
  • Back
List five criteria, taken together, comprise a reasonable definition of an animal.
1. Animals are multicellular, ingestive heterotrophs
2. Animal cells lack cell walls that provide structural support for plants and fungi
3. Animals have two unique types of cells: nerve cells for impulse conduction and muscle cells for movement.
4. Most animals reproduce sexually, with the diploid stage usually dominating the life cycle
5. Animals share a unique homeobox-containing family of genes known as Hox genes
The zygote undergoes _____
a succession of mitotic cell divisions, leading to the formation of a multicellular, hollow ball of cells called the _______.
During _______ part of the embryo folds inward, forming layers of embryonic tissues that will develop into adult body parts.  The resulting development stage is called a ______.
gastrulation, gastrula
Some animals develop directly through transient stages into adults, but others have ________________.
distinct larval stage or stages
A _____ is a sexually immature stage that is morphologically distinct from the adult, usually eats different foods, and may live in a different habitat from the adult
Animal larvae eventually undergo _____ transforming the animal into an adult.
Many of these regulatory genes contain common modules of DNA sequences called _____.
All animals share the unique family of Hox genes, suggesting that __________.
this gene family arose in the eukaryotic lineage that gave rise to animals