Many enzymes are named for the substrate on which they work, either to build or disassemble molecules. Also, enzyme names often end in "-ase." For example, lactase is the enzyme that breaks down lactose. With a name like "telomerase," we can deduce that telomerase is probably:

A taxon that includes a single common ancestor and all its descendants is a _____ group

A. monophyletic B. paraphyletic C. polyphyletic

During ____ , N2 within the atmosphere is converted to NH3. Primary producers can then use the nitrogen from NH3 to build organic compounds

Fill in the blank with the appropriate word.

After a muscle cell contracts, which of the following must occur for the muscle to stop contracting?

A. Calcium ions must be pumped back into the endoplasmic reticulum. B. Calcium ions must flow out of the endoplasmic reticulum. C. Calcium ions must flow into the muscle cell. D. Calcium ions must flow out of the muscle cell. E. Calcium ions must be pumped out of the muscle cell.

Which of the following is not a characteristic of fungi?

1.They are more closely related to animals than to plants. 2.They are autotrophic. 3.They secrete enzymes and absorb nutrients. 4.They can be parasites.