What will happen if a chemical prevents the neurotransmitter from attaching to its
receptor on the next cell?

If the receptor sites for the neurotransmitter are blocked, the neurotransmitter is not able to act on that receptor. Most of the time, the neurotransmitter will then be taken back up by the neuron that released it, in a process known as "reuptake".

Explanation:

answer: populations of walruses and polar bears will decline

explanation:

you put it

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.