In a living thing, both tissue and organs are very important to maintaining homeostasis.
The best answer is A.
The shape of a protein is determined by its primary structure. The primary structure is the sequence of amino acids in each polypeptide chain which make up a protein.
The sequence of amino acids is basically a list of amino acids that are linked to each other to form a chain which is known as a polypeptide chain.
The structure of the finished protein will depend largely on the first (primary) chain of amino acids to be produced to make up that protein.
B. transport oxygen to tissues
An animal that hides under a rock to avoid predators is responding to an instinctive stimulus.
