How many b genes are necessary to produce the recessive color

For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent. An individual with one dominant and one recessive allele for a gene will have the dominant phenotype. They are generally considered “carriers” of the recessive allele: the recessive allele is there, but the recessive phenotype is not. so in short, 2

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Albinism shows a genetic disorder, which is characterized by absence of coloration or pigmentation in individuals. It is an autosomal recessive disorder that transmits from parents to their offspring, when offspring receives both the mutated copies of gene responsible for albinism.

For a genetic disorder, dominant or wild type allele is represented by capital letter, such as 'A', while recessive or mutated allele is represented by small letter, 'a'. As 4th picture is representing male and female gametes with recessive alleles (a) , the resulting zygote will have both recessive alleles for albinism (aa), '4th zygote will develop into an albino child.'