The correct option is A.
Fitness refers to the quantitative representation of natural and sexual selection within an evolution. Fitness can be defined in respect to a genotype or a phenotype. Relative fitness is described as the survival or reproductive rate of a genotype or phenotype relative to maximum survival or reproductive rate of other genotypes in the population. Thus, the fitness of a population can be determined by finding out the number of offspring that survive to adulthood.
Answer:
b. form of a gene
Explanation:
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ.