In a plant , red fruit (R) dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTT genotype is crossed with a plant that is rrtt. Then

Options

A. 25% will be tall with red fruit
B. 50% will be tall with red fruit
C. 75% will be tall with red fruit
D. All of the offspring will be tall with red fruits

Answer

To solve the problem, we need to analyze the genetic cross between two plants with the given genotypes.

### Step-by-Step Solution:

1. **Identify the Genotypes:**
- The first plant has the genotype RRTT (homozygous for red fruit and tall).
- The second plant has the genotype rrtt (homozygous for yellow fruit and short).

2. **Determine the Gametes:**
- The first plant (RRTT) can only produce one type of gamete: RT (since it is homozygous for both traits).
- The second plant (rrtt) can also only produce one type of gamete: rt.

3. **Perform the Cross:**
- When we cross the two plants, we combine the gametes:
- RRTT (RT) x rrtt (rt)
- The offspring will inherit one allele from each parent for each trait.

4. **Genotype of the Offspring:**
- All offspring will have the genotype RrTt (heterozygous for both traits).

5. **Phenotype of the Offspring:**
- Since R (red fruit) is dominant over r (yellow fruit), all offspring will exhibit red fruit.
- Since T (tall) is dominant over t (short), all offspring will be tall.
- Therefore, all offspring will have red fruit and be tall.

6. **Conclusion:**
- The answer is that all of the offspring will be tall with red fruits.

### Final Answer:
**D. All of the offspring will be tall with red fruits.**