If two genes show 50% recombination frequency , then Which of the following statement is not correct about it ?

Options

A. The genes may be on different chromosomes .
B. The genes are tightly linked.
C. The genes show independent assortment.
D. The genes are present on the same chromosome, they undergo crossing over in meiosis .

Answer

To solve the question regarding the recombination frequency of two genes, we need to analyze the implications of a 50% recombination frequency and evaluate the provided statements.

### Step-by-Step Solution:

1. **Understanding Recombination Frequency**:
- Recombination frequency is a measure of the likelihood that two genes will be separated during meiosis due to crossing over. A 50% recombination frequency indicates that the genes are assorting independently, similar to genes located on different chromosomes.

**Hint**: Remember that a recombination frequency of 50% suggests independent assortment.

2. **Evaluating the Statements**:
- **Statement 1**: "The genes may be on different chromosomes."
- This statement is correct. Genes located on different chromosomes will assort independently and can show a recombination frequency of 50%.

**Hint**: Consider the chromosome theory of inheritance when assessing this statement.

- **Statement 2**: "The genes are tightly linked."
- This statement is incorrect. Tightly linked genes would have a low recombination frequency because they are located close to each other on the same chromosome. A 50% recombination frequency indicates that they are not tightly linked.

**Hint**: Think about the physical distance between genes on a chromosome and how it affects recombination.

- **Statement 3**: "The genes are for independent assortment."
- This statement is correct. A recombination frequency of 50% indicates that the genes assort independently, which is a key principle of Mendelian genetics.

**Hint**: Recall Mendel’s laws regarding independent assortment.

3. **Conclusion**:
- The statement that is **not correct** is: "The genes are tightly linked." This is because tightly linked genes would not show a 50% recombination frequency.

### Final Answer:
The statement that is not correct is: "The genes are tightly linked."