Question

If B represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the phenotypic ratio of a cross between a heterozygous black-eyed MendAlien and an orange-eyed MendAlien?a. 3 black : 1 orangeb. 1 black : 0 orangec. 1 black : 1 oranged. 0 black : 1 orangee. 1 black : 3 orange

Answer 1

1 black : 1 orange

Explanation:

• The heterozygous black eyed MendAllen will have both type of alleles B and b. But B being dominant will express itself and the individual will be black eyed.(Genotype-Bb)
• During meiosis two types of Gametes will be produced by this individual. One type of gamete will have the dominant allele and other type will contain the recessive allele.
• The orange eyed MendAllen will produce only one type of gametes that will have the recessive allele. (Genotype-bb)

When the above stated individual will be crossed the following combination of allele will be seen:

• Bb- Black eyed
• bb-orange eyed

Thus, the phenotypic ratio of offspring will be 1black :1 orange.