Answer: Base pairs are formed when adenine forms a hydrogen bond with thymine, or cytosine forms a hydrogen bond with guanine. The second part of a nucleotide is the phosphate, which differentiates the nucleotide molecule from a nucleoside molecule.
Explanation:
<span>As blood moves away from the heart toward the tissues, the relative size of blood vessels decreases, the blood pressure drops, and the velocity of blood flow slows.
The size of the arteries progressively decreases as they branch out from the major arteries of the body. Once the arteries are the size of the arterioles, the resistance to blood flow increases and velocity of blood flow slows then blood pressure drops.
</span>
Answer:
Ecological and ethological approaches to the study of behaviour. The natural history approach of Darwin and his predecessors gradually evolved into the twin sciences of animal ecology, the study of the interactions between an animal and its environment, and ethology, the biological study of animal behaviour.
Answer:
B an animal that can live in fresh water
2 with D and 1 with E and