In radishes, red and white are pure-breeding colors, while hybrids are purple. if a red radish is crossed with a white radish, what will be the phenotype of the f2 generation assuming the f1 generation self- pollinates? show the punnett square.

The answer is 1 red radish, 2 purple radishes, and 1 white radish

Let R allele be dominant allele over r allele. The genotypes and phenotypes will be as following:
RR - red radish
rr - white radish
Rr - purple radish

Parental generation:       RR      x      rr
F1 generation:             Rr      Rr    Rr     Rr

Since the F1 generation self-pollinates, we have the situation:
F1 generation:             Rr    x    Rr
F2 generation:         RR   Rr    Rr    rr

Punnet square:
                                 Rr            
                          R      |   r
             R   |     RR    |   Rr
Rr           r   |     Rr      |  rr

So, there will be 1 red radish (RR), 2 purple radishes (Rr), and 1 white radish (rr)