Name: Sex Determination (Drosophila melanogaster)
Uploaded: 2019-07-19
Duration: 7 min 20 s
Description: Drosophila melanogaster or the common fruit fly has contributed a lot to genetics. One of them is its sex determination system with more than five types of s...

Question

Schematically represent the inheritance of two genes in pea plants with reference to seed colour and shape.

Accepted Answer

A Dihybrid cross is a cross between two different lines/genes that differ in two observed traits. In the Mendelian sense, between the alleles of both these loci, there is a relationship of complete dominance-recessive. The phenotypic distribution would be in such a way that parental combination is more frequency of recombination is less depending on the strength of linkage.

A dihybrid cross is a cross between F₁ offspring of two individuals that differ in two traits of a particular interest. For example, Mendel took homozygous dominant Round and yellow seeds (RRYY) and crossed it with homozygous recessive wrinkled and green seeds (rryy), the progeny obtained in F₁generation were all round and yellow seed (RrYy). The offsprings were heterozygous for both R and Y gene. The F₁ plant has four types of gametes, RY, Ry, rY, and ry.

Thus, by crossing F₁, the phenotypic ratio was 9:3:3:1, where 9 is yellow and round seeds, 3 represents round and green seeds, 3 represents yellow and wrinkled seeds and 1 represents green and wrinkled seeds.

Schematically represent the inheritance of two genes in pea plants with reference to seed colour and shape.

Important Questions on Principles of Inheritance and Variation

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