The selection of more effective which is against recessive alleles in haploid organisms than diploid organisms. This is because haploid organisms contain a single set of alleles if a deleterious allele is present in haploid organisms which will produce its effect immediately as there will be no dominant allele which can prevent the expression of the recessive allele as it happens in diploids. Recessive allele will not produce its effect in presence of the dominant allele in the case of heterozygote which is Aa. Where there is haploid the selection will be more effective when removing recessive alleles in the population. It is the homozygous recessive condition which as aa then the selection will act against recessive alleles.
