The three main worm phyla are flatworms, roundworms, and segmented worms. Roundworms have a digestive tube that has two openings. Segmented worms have a closed circulatory system in which blood is enclosed in blood vessels. These are important steps in the evolutionary development of animals.
Answer:
The hemoglobin molecule has four binding sites for oxygen molecules: the iron atoms in the four heme groups. Thus, each Hb tetramer can bind four oxygen molecules.
The step that is an important part of the process by which ecology guides humans to a sustainable future is that behavior is changed after the cause of the problem is identified. The correct answer is D.
Answer:
that's very broad, is that the whole question?
