Round seed trait ( R) is dominant over wrinkled ( r) seed trait in Pea. Heterozygous round seede plant (Rr) is crossed with wrinkled seeded plant (rr). What is the possible progeny ?

Options

A. 302round :102 wrinkled
B. 210 round: 95 wrinkled
C. 105 round : 99 wrinkled
D. 103 round :315 wrinkled

Answer

To solve the problem of determining the possible progeny from a cross between a heterozygous round-seeded plant (Rr) and a wrinkled-seeded plant (rr), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Traits and Alleles**:
- Round seed trait (R) is dominant.
- Wrinkled seed trait (r) is recessive.
- The genotypes of the plants involved in the cross are:
- Heterozygous round seed plant: Rr
- Wrinkled seed plant: rr

2. **Determine the Gametes**:
- The heterozygous plant (Rr) can produce two types of gametes: R (dominant) and r (recessive).
- The wrinkled-seeded plant (rr) can only produce one type of gamete: r (recessive).

3. **Set Up the Punnett Square**:
- Create a Punnett square to visualize the possible combinations of gametes from the two parents.
```
R | r
-----------------
r | Rr | rr
-----------------
r | Rr | rr
```

4. **Fill in the Punnett Square**:
- The combinations from the gametes will result in:
- Rr (Round seed) from R and r
- rr (Wrinkled seed) from r and r
- Thus, the offspring genotypes are:
- Rr (Round) and rr (Wrinkled)

5. **Count the Progeny Ratios**:
- From the Punnett square, we see:
- 2 Rr (Round seeds)
- 2 rr (Wrinkled seeds)
- Therefore, the ratio of the progeny is:
- 1 Rr : 1 rr

### Conclusion:
The possible progeny from the cross between a heterozygous round-seeded plant (Rr) and a wrinkled-seeded plant (rr) will be in the ratio of 1:1, with 50% round seeds and 50% wrinkled seeds.