Biology help A gardener wants to perform a test cross to det

Biology help.

A gardener wants to perform a test cross to determine the genotype of a certain breed of a flower. She wants to know if the plan BB or Bb. (B is the allele for the blue flower color and b is the allele for white flower color.) Given that normal rules of dominant and recessive genes apply, whith what genotype of plant should the cross be performed-BB, Bb, bb? Explain your answer.

Solution

Answer:

Test cross is the cross between the F1 hybrid and the homozygous recessive parent (bb)

F1 hybrib is developed, when the two pure breeding plants are crossed.

1). If the F1 plant is having genotype BB, all progeny of the test cross are dominant phenotype with Bb genotype.

BB(F1) X bb (homozygous recessive parent)

Bb (progeny)

2). If the F1 plant is having genotype Bb, all progeny of the test cross are 50% dominant phenotype with Bb genotype and the remaining 50% are recessive with bb genotype

Bb(F1) X bb (homozygous recessive parent)

Bb : bb = 1 : 1  (progeny)