Question

What is a Punnett square?

Answer 1

Punnett square :

1. A diagram that represents the possible genotypes of offspring, developed after the event of breeding.
2. It was first developed by geneticist Reginald Punnette.
3. The possible genotypes of offspring are represented in tabular form.
4. Each box in the table represents one event of fertilization.
5. Each allele in every Punnett square is represented by the first letter of the dominant phenotype

Example: Seed color in pea plant :

1. The seed color in pea plants is an example of a monohybrid cross.
2. The dominant phenotype in seed color pea plants is yellow and the recessive phenotype is green color.
3. The cross is done using Punnett square between pea plants with yellow color seeds (YY) and pea plants with green color seeds (yy).
4. The Punnett square is used for finding out the probability of all possible genotypes of offspring in a cross of YY and yy.
5. The dominant alleles of yellow trait YY and recessive alleles of green trait yy segregate to form gametes.
6. The gametes are represented outside the 2X2 table.
7. The cross results in F1 progeny with Yy ( genotype) and yellow color seeds (phenotype).