When do cells differentiate? That is, when do cells first become different kinds of cell—muscle cells, nerve cells, reproductive cells, etc.?

A. during the 1st trimester
B. before fertilization
C. during the 3rd trimester
D. during the 2nd trimester

Answer is A

i think it’s c but i might be wrong. if i am let me know! have a good rest of your day as well!

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms

i won't lie i don't know so go online and ask google thats what i do