Answer:
Endocrine system uses chemical signaling (hormones produced by glands) while the nervous system uses electrical signaling (neural impulses).
The right answer is B.
Mutations are not always unfavorable, they are often "indifferent" as to the survival of the cells or the individual.
Mutations are the primary source of variation in the genetic material underlying the evolution of living things. They can have a beneficial effect for the species.
First they don't use oxygen, plants use the CO2 in the air and release oxygen out into the air after the plant used up the CO2
