Answer:
Acetylcholine
Explanation:
Acetylcholine is an organic chemical that functions in the brain and body of many types of animals and humans as a neurotransmitter.
Are you taking about how the giraffe changed overtime to survive better in its surroundings? If so, the giraffe has evolved (changed) to have a long neck/legs to be able to reach leaves from high trees, those giraffes who fall short (literally) die off and then all there is left is the tall ones who can survive better and longer.
Answer:
False. A with T and C with G
Explanation: