In monohybrid cross, What is the possibility of obtaining genotype TT, tt and Tt respectively in `F_(2)` generation :

Options

A. 3/4, 1/4, 1/2
B. 1/4, 1/4, 1/2
C. 1/4, 1/2, 1/4
D. 1/2, 1/2, 1/4

Answer

To solve the question regarding the possibility of obtaining the genotypes TT, tt, and Tt in the F2 generation of a monohybrid cross, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Monohybrid Cross**:
- A monohybrid cross involves one trait, typically represented by two alleles. In this case, we have tall plants (T) and dwarf plants (t).

2. **Identify the Parent Genotypes**:
- The parents are homozygous: one parent is TT (tall) and the other is tt (dwarf).

3. **Determine the F1 Generation**:
- When these parents are crossed (TT x tt), all offspring in the F1 generation will be heterozygous (Tt), which means they will all be tall plants.

4. **Self-Cross the F1 Generation**:
- Next, we self-cross the F1 generation (Tt x Tt) to produce the F2 generation.

5. **Create a Punnett Square**:
- Set up a Punnett square to determine the genotypes of the F2 generation:
```
T t
-----------
T | TT | Tt |
-----------
t | Tt | tt |
```
- From the Punnett square, we can see the possible genotypes:
- TT (homozygous tall)
- Tt (heterozygous tall)
- tt (homozygous dwarf)

6. **Count the Genotypes**:
- The results from the Punnett square show:
- 1 TT
- 2 Tt
- 1 tt

7. **Calculate the Ratios**:
- The total number of offspring is 4 (1 TT + 2 Tt + 1 tt).
- Therefore, the probabilities are:
- Probability of TT = 1/4
- Probability of Tt = 2/4 = 1/2
- Probability of tt = 1/4

8. **Final Result**:
- The probabilities of obtaining the genotypes TT, Tt, and tt in the F2 generation are:
- TT: 1/4
- Tt: 1/2
- tt: 1/4

### Summary of Probabilities:
- TT: 1/4
- Tt: 1/2
- tt: 1/4