Answer:
B. hydrogen bond
Explanation:
The double helix is held together by hydrogen bonds between the bases
Answer:
Averaging the fitness of its members.
Explanation:
The fitness of a whole population can also be determined by averaging the fitness of its members. Absolute fitness is the ratio between the number of individuals with a genotype before selection versus after selection. Fitness is usually discussed in terms of genotypes, or collection of genes.
Answer:
four oxygen molecules
Explanation:
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.