The answer is (C) Replication
Though occasional errors could occur in cells during replication; the cells have error checking and proofing mechanisms that reduce the rate of error to one to several million replications in higher eukaryotes.
After all, one mismatch error during replication would not result in major effects. The others choices, however, have higher rates of causing genetic abnormalities.
The pollen grains contain sperm which will fertilize the egg and create a seed to sprout the next generation of plants. The main male part is the stamen. It is divided into two parts: the anther and the filament. The anther produces the pollen grains that contain the sperm needed for fertilization.
Prokaryotic cells don't have a nucleus
Because of the way builds up in your body