Repeating DNA regions of at least 1000 base pairs known as ____________________ can affect gene expression. Fill in the blank(s) with the appropriate word(s)

All of the following statements about exoskeletons are correct except

A. muscles are attached to the exoskeleton. B. exoskeletons do not limit growth because they can stretch. C. exoskeletons are shed by many arthropods in a process called molting. D. exoskeletons are made of chitin. E. chitin is a polysaccharide.

Circular DNA molecules found in nature are

A) positively supercoiled. B) negatively supercoiled. C) not supercoiled, due to their small size. D) always oriented in a triple helix to conserve space. E) always in the Z-DNA formation.

In eukaryotic cells, we sometimes find reverse transcriptase activity, even though the cells are not infected with a retrovirus. This activity can be attributed to

A) the presence of transposons integrating into polymerase genes. B) the presence of viroids. C) the presence of retrotransposons. D) infection with small bacteria known as mycoplasmas. E) a novel prion infection.

Alcids and penguins have had similar adaptations selected despite them being in different groups. What is this an example of?

a. Synchronous evolution b. Convergent evolution c. Concise evolution d. Divergent evolution