Answer:
Mutations and sexual reproduction increase genetic variation in a population. Natural selection occurs when environmental pressures favor certain traits that are passed on to offspring. ... Individuals may mutate, but natural selection acts by shifting the characteristics of the population as a whole.
Explanation:
Pollen....because cones are absent in angiosperms.....flowers are absent in gymno....and seeds are also absent in gymno sperm........so and is pollen !