Question

Alleles of the gene that determines seed coat patterns in lentils can be organized in a dominance series:Marbled > Spotted = Dotted > ClearA lentil plant homozygous for the marbled seed coat pattern allele was crossed to one homozygous for the spotted pattern allele. In another cross, a homozygous dotted lentil plant was crossed to one homozygous for clear. An F1 plant from the first cross was then mated to an F1 plant from the second cross.What are the expected phenotypes of the F1 plants from the two original crosses?

Answer 1

Answer:

first original cross = 100 % marbled seed coat lentils

second original cross = 100% dotted seed coat lentils

Explanation:

Given,

Marbled > Spotted = Dotted > Clear ( Spotted and dotted alleles are codominant )

Let, marble = m

spotted = s

dotted = d

clear = c

First original cross: mm * ss :

    m    m

s  ms   ms

s  ms   ms

Entire progeny has ms genotype. Since m is dominant over s, result will be 100% marbled seed coat lentils.

Second original cross : dd * cc :

     d      d

c   dc     dc

c   dc     dc

Entire progeny has dc genotype. Since d is dominant over c, result will be 100 % dotted seed coat lentils.