In monohybrid cross what is the ratio of homozygous dominant and homozygous recessive individuals in `F_(2)` generation :-

Options

A. `1:2:1`
B. `2:1//1:2`
C. `3:1//1:3`
D. `1:1`

Answer

To solve the question regarding the ratio of homozygous dominant and homozygous recessive individuals in the F2 generation of a monohybrid cross, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Monohybrid Cross**:
A monohybrid cross involves a single trait with two alleles, one dominant and one recessive. For example, let's consider the trait of plant height where 'T' represents tallness (dominant) and 't' represents shortness (recessive).

2. **Parental Generation (P)**:
We start with two homozygous parents: one homozygous dominant (TT) and one homozygous recessive (tt).
- Parental Genotypes:
- Tall (homozygous dominant): TT
- Short (homozygous recessive): tt

3. **First Filial Generation (F1)**:
When we cross these two parents (TT x tt), all offspring in the F1 generation will be heterozygous (Tt).
- F1 Genotype: Tt (All plants are tall)

4. **Second Filial Generation (F2)**:
To obtain the F2 generation, we cross two F1 individuals (Tt x Tt). We can use a Punnett square to determine the genotypes of the offspring.
- Punnett Square:
```
T | t
-----------------
T | TT | Tt
-----------------
t | Tt | tt
```

5. **F2 Generation Genotypes**:
From the Punnett square, we can see the genotypes of the F2 generation:
- TT (homozygous dominant): 1
- Tt (heterozygous): 2
- tt (homozygous recessive): 1

6. **Calculating the Ratio**:
The ratio of the genotypes in the F2 generation is:
- 1 TT : 2 Tt : 1 tt
- To find the ratio of homozygous dominant (TT) to homozygous recessive (tt), we look at the counts:
- Homozygous dominant (TT): 1
- Homozygous recessive (tt): 1
- Therefore, the ratio of homozygous dominant to homozygous recessive is 1:1.

### Final Answer:
The ratio of homozygous dominant (TT) to homozygous recessive (tt) individuals in the F2 generation is **1:1**.