Author: Anonymous

The first animals arose about 570 million years ago. They probably resembled aquatic protists called choanoflagellates.

Echinoderm adults have five-part radial symmetry

How many of the following animals have bilateral symmetry?  

Any muscle movement that lengthens the muscles and results in an increased angle of the joint is

Which structure is 2,3-dimethyl pentane?

In ———–, part of a population enters a new habitat bordering the range of the parent species. Mating can occur between populations, but most individuals mate with their own population.

The biological species concept cannot be applied to

Which of the following can evolve (according to the biological definition of evolution)?

Evolution occurs in populations but not in individuals.

Radiometric dating: measures the amount of —– in a fossil to calculate how long ago the organism died