A certain plant homozygous for yellow seeds and red flowers was crossed with a plant homozygous for green seeds and white flowers. The F₁ plants had yellow seeds and pink flowers. The F₁ plants were selfed to get F₂ progeny. Assuming independent assortment of the two characters, how many phenotypic categories are expected for these characters in the F₂ generation ?

To determine the number of phenotypic categories expected in the ${\mathrm{F}}_2$ generation, we need to consider the possible combinations of alleles from the two parental plants.

Let’s assign the following symbols to represent the alleles for seed color and flower color:

Yellow seed color (Y) and green seed color (y)
Red flower color (R) and white flower color (r)

Since the plant homozygous for yellow seeds and red flowers (YYRR) is crossed with a plant homozygous for green seeds and white flowers (yyrr), the ${\mathrm{F}}_1$ generation will have the genotype YyRr (heterozygous for both traits) and the phenotype will be yellow seed color and pink flower color.

When the ${\mathrm{F}}_1$ generation is self-pollinated, the possible gametes produced are YR, Yr, yR and yr, as a result of independent assortment. These gametes can combine in various ways to produce different genotypes in the ${\mathrm{F}}_2$ generation.

Seed color:
1. YY / Yy (yellow)
2. yy (green)
Flower color:
1. RR (red)
2. Rr (pink)
3. rr (white)
The possible phenotypes in the ${\mathrm{F}}_2$ generation:

•  Yellow seed color, red flower color
•  Yellow seed color, pink flower color
•  Yellow seed color, white seed color
•  Green seed color, red flower color
•  Green seed color, pink flower color
•  Green seed color, white flower color

Therefore, there is a total of 6 phenotypes.