Question

In a different plant species from the example given, flower color is controlled by two genes that contribute equally to pigmentation in the final flower color. The more "R" alleles, the more pigmentation, such that only plants with the genotype CRCR DRDR have red flowers, and only plants with the genotype CWCW DWDW have white flowers. Plants with three "R" alleles produce 75% as much pigmentation as CRCR DRDR plants and have dark pink flowers. Plants with three "W" alleles produce 25% as much pigmentation as CRCR DRDR plants and have light pink flowers. Plants with an equal number of "R" and "W" alleles produce 50% as much pigmentation as CRCR DRDR plants and have pink flowers. A red flowering plant was mated to a white flowering plant and all of the F1 progeny had pink flowers. These pink flowered F1 plants were allowed to self-fertilize to produce F2 progeny. What is the genotype of the F1 plants that produced pink flowers? (Hint: draw Punnett squares to determine the F1 and F2 genotypes and phenotypes.)

A) CWCW DRDR
B) CRCW DRDW
C) CWCR DRDR
D) CRCR DWDW

Answer 1

The genotype of the F1 plants that produced pink flowers is CRCW DRDW

Step-by-step explanation:

A red flowering plant is an individual with 4 R alleles and genotype CRCRDRDR. It was mated to a white flowering plant which is an individual with 4 W alleles and genotype CWCWDWDW. This is:

P) CRCR DRDR x CWCW DWDW

All of the F1 progeny had pink flowers, that means that all the individual of the F1 generation have 2 R alleles and 2 W alleles, and their genotype is CRCWDRDW.

Punnett square

P) CRCR DRDR X CWCW DWDW

F1)

CRDR CRDR CRDR CRDR CWDW CRCW DRDW CRCW DRDW CRCW DRDW CRCW DRDW CWDW CRCW DRDW CRCW DRDW CRCW DRDW CRCW DRDW

CWDW CRCW DRDW CRCW DRDW CRCW DRDW CRCW DRDW

CWDW CRCW DRDW CRCW DRDW CRCW DRDW CRCW DRDW

CWDW CRCW DRDW CRCW DRDW CRCW DRDW CRCW DRDW

F1 Genotype: 100% CRCW DRDW. Equal ampunts of R and W alleles.

F1 Phenotype: 100% Pink. 50% as much pigmentation as CRCR DRDR parent.