In monohybrid cross (Tt x Tt), percentage of homozygous plant is______

Answer

To solve the question regarding the percentage of homozygous plants in a monohybrid cross (Tt x Tt), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Cross**:
- We are performing a monohybrid cross between two heterozygous parents (Tt x Tt). Here, 'T' represents the dominant allele and 't' represents the recessive allele.

2. **Determine the Gametes**:
- Each parent can produce two types of gametes: T and t. Therefore, the gametes from both parents are:
- Parent 1: T, t
- Parent 2: T, t

3. **Set Up a Punnett Square**:
- Create a 2x2 Punnett square to visualize the possible combinations of the gametes:
```
T t
----------------
T | TT | Tt |
----------------
t | Tt | tt |
----------------
```

4. **Identify the Offspring Genotypes**:
- From the Punnett square, we can see the possible genotypes of the offspring:
- TT (homozygous dominant)
- Tt (heterozygous)
- Tt (heterozygous)
- tt (homozygous recessive)

5. **Count the Homozygous Plants**:
- The homozygous plants are:
- TT (1)
- tt (1)
- Therefore, there are a total of 2 homozygous plants.

6. **Calculate the Percentage of Homozygous Plants**:
- The total number of offspring is 4 (TT, Tt, Tt, tt).
- The percentage of homozygous plants is calculated as follows:
\[ \text{Percentage of homozygous plants} = \left( \frac{\text{Number of homozygous plants}}{\text{Total number of offspring}} \right) \times 100 \]
\[ = \left( \frac{2}{4} \right) \times 100 = 50\% \]

### Final Answer:
The percentage of homozygous plants in the monohybrid cross (Tt x Tt) is **50%**.