What characterizes a population with a rare recessive allele?

A population characterized by a rare recessive allele typically exhibits a low allele frequency, meaning that the recessive allele occurs infrequently in the gene pool. In such cases, the individuals who express the recessive trait (homozygotes) are often quite rare because they must inherit the recessive allele from both parents.

Consequently, since the recessive allele is not common, heterozygotes, who carry one copy of the recessive allele and one dominant allele, are generally more prevalent than homozygotes in the population. However, if the allele is rare, heterozygotes may not be abundant relative to the overall population size.

Thus, the correct answer aligns with the understanding that a rare recessive allele will result in the increased likelihood of individuals being heterozygous (carriers) rather than homozygous recessive. In most populations, heterozygotes often exist in greater numbers than either homozygous dominant or homozygous recessive individuals when considering a rare recessive allele. Therefore, while option A states that heterozygotes are abundant, it is important to note that the context of rarity also allows a higher presence of heterozygotes compared to homozygous recessive individuals.