Respuesta :

1 hormones
2 external stimuli

Answer:

Hormones

Explanation:

Hormones are the chemical messengers secreted by endocrine glands. Various hormones have their respective impact on the functioning of body. Human growth hormone is the hormone that promotes the growth and development of organisms by stimulating the cells to divide to produce the new cells. Hence, hormones can stimulate cell regulators to increase cell reproduction.