Explanation:when we are hungry.we crave for food and eat.
the stimulus is when we are hungry
the response that come from brain is that order us to eat
the stimulie is internal.
hope this will help
Answer:
Thymine and uracil or adenine have two hydrogen bonds between them, whereas guanine and cytosine have three.
A Sertoli cell (a kind of sustentacular cell) is a "nurse" cell of the testicles that is part of a seminiferous tubule and helps in the process of spermatogenesis; that is, the production of sperm.
It is activated by follicle-stimulating hormone (FSH) secreted by the adenohypophysis, and has FSH receptor on its membranes. It is specifically located in the convoluted seminiferous tubules (since this is the only place in the testes where the spermatozoa are produced). Development of Sertoli cells is directed by the testis-determining factor protein.