Question

Long after Mendel’s Laws were accepted it was observed that crosses between homozygous red snapdragons and homozygous white snapdragons produced "pink" snapdragons. This is exactly what the blending inheritance model told Mendel to expect when he bred his peas! Is this still a case of Mendelian inheritance? If not, why not? If so,how do you explain it? What would happen if you crossed two of the pink flowers?

Answer 1

Blending inheritance theory is different from inheritance theory of Mendel

RW * RW

RR, RW, RW, WW

Two pink, one red and one white flower.

Step-by-step explanation:

As per Mendel, two different traits associated with two different allele assort independently. They do not interfere with the expression of characteristics associated with any of the two allele.

However, in the case of snapdragon two different traits get mixed and an intermediate trait is produced i.e pink colour out of parent’s red and white color.

Let us say the allele for red flower is “R” and the allele for white flower is W

Then the genotype of pink flower is “RW”

On crossing two pink flowers, following offspring would be produced –

RW * RW

RR, RW, RW, WW

Two pink, one red and one white flower.