Based on scientific research, which statement best describes mutations? a. mutations are rare occurrences. b. mutations are always harmful. c. mutations cannot be inherited. d. mutations cannot be acquired.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.