Mutations and sexual reproduction aid evolution by providing ..
a.) variation between individuals
b.) oxygen for life
c.) the theory of evolution
d.) comparison between species

How does secondary succession differ from primary succession?

Moving down the ramp from 6 meters to

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.