In pea plants, spherical seeds (S) are dominant to dented seeds (s). I...
Pea Plant Inheritance:
Pea plants were used by Gregor Mendel in his experiments on inheritance. He identified different traits in pea plants that were inherited in a predictable pattern. One of the traits he studied was seed shape.
Dominant and Recessive Traits:
In pea plants, spherical seeds (S) are dominant to dented seeds (s). This means that if an individual plant has at least one copy of the S allele, it will have spherical seeds. If an individual has two copies of the s allele, it will have dented seeds.
Heterozygous Cross:
When two plants that are heterozygous for the seed shape trait are crossed (Ss x Ss), there are three possible genotypes for the offspring:
- SS (spherical seeds homozygous)
- Ss (spherical seeds heterozygous)
- ss (dented seeds homozygous)
The Punnett square for this cross looks like this:
| | S | s |
|---|---|---|
| S | SS | Ss |
| s | Ss | ss |
There is a 25% chance of getting SS offspring (spherical seeds homozygous), a 50% chance of getting Ss offspring (spherical seeds heterozygous), and a 25% chance of getting ss offspring (dented seeds homozygous).
Probability of Spherical Seeds Heterozygous:
The question asks for the probability of getting offspring that are spherical seeds heterozygous (Ss). Looking at the Punnett square, we can see that there are two possible ways to get Ss offspring:
- From the SS x Ss mating, where all offspring are Ss
- From the Ss x ss mating, where half of the offspring are Ss
Therefore, the probability of getting Ss offspring is 0.50 or 50%.