Breathing in humans is driven by all of the following except A. the muscles attached to the ribs. B. the diaphragm. C. air pressure. D. the muscles connected to the lungs.

What prevents antibiotics from being effective against viruses?A. Viruses have a high rate of mutation.
B. Viruses have no RNA.
C. Viruses have no metabolism.
D. Viruses have a protein shell that protects them.

The pH of water is _____ because it contains an equal amount of H+ and OH- ions.

Which one of the following statements holds true for the induced-fit model?a. Once the enzyme binds to the specific substrate molecule, no structural changes can occur in the active site of the enzyme.
b. Once the enzyme binds to the specific substrate molecule, structural changes can occur in the active site to accomodate the product.
c. Once the enzyme binds to a specific substrate molecule, subtle structure changes occur in the active site, which are reverted when the reaction is over.

Which of these is responsible for ridding the body of waste?A) nervous system
B) Excretory System
C) Circulatory System
D) Reproductive System

Which of the following statements is true?Lysosomes and chloroplasts are unique to plant cells.
Instead of a cell membrane, plant cells have cell walls.
Homeostasis on the cellular level is controlled by the cell membrane.
A nerve cell contains more mitochondria than a muscle cell.

In plant cells, this structure captures energy from the sun to produce food.