Question

Suppose you have monohybrid snapdragons in your garden and you find that they produce red seeds to white seeds in the ratio of 3:1. If the alleles are designated R (red seeds) and r (white seeds), what are the probable phenotypes of the parents (P1)?

Answer 1

They parents would both be "half red and half white" making them heterozygous or Rr and Rr
Since when put into a punnet square it produces the 3:1 result

Answer 2

Answer:

Parents are both red-seeded (Rr)

Explanation:

The gene involved here is that of seed colour in snapdragons. Red allele (R) and white allele (r) are the two forms of the colour gene. According to the question, the offsprings are in the ratio 3red:1white. This ratio means that there are 3 red-seeded offsprings and 1 white-seeed offspring.

Based on this, the red allele (R) is dominant over the allele for white (r). This means that the red trait can be expressed in a homozygous or heterozygous state while the white trait can only be expressed in a homozygous state. Hence, this 3:1 ratio can only be experienced if both parents (P1 generation) are heterozygous.

This would produce offsprings with genotype: RR, Rr, Rr, rr

RR, Rr, and Rr are all phenotypically red while rr are phenotypically white