Which of the following groups does not exhibit bilateral symmetry?

A species of rotifer, a small freshwater invertebrate, lost the ability to reproduce sexually millions of years ago. A remarkable feature of its life cycle is the ability to withstand dry conditions. When the rotifer's environment dries out, so does the rotifer, and it can be blown to a new area. Rotifers that land in water will rehydrate and resume an active life. A major pathogen of these rotifers is a species of fungus that cannot survive drying. Some scientists hypothesize that drying rids the rotifers of this pathogen. (b) Why might the ability to withstand drying reduce any potential advantage of sexual reproduction in this rotifer species?

Which of the listed characteristics is shared by plants, fungi, and animals?

Animals probably evolved from colonial protists. How do animals differ from these protist ancestors?

Many young animals are __________, a sexually immature form that is morphologically distinct from the adult stage. These young animals undergo __________ to become __________, which resemble adults but are not yet sexually mature.

Which of the following is a characteristic of cnidarians?

In the embryo of a shark, ectoderm gives rise to __________; mesoderm gives rise to __________; endoderm gives rise to __________.

Which of the following is the defining characteristic of the clade Ecdysozoa for which this group is named?

Unlike other animals, sponges __________.