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Consider the following statements regard...

Consider the following statements regarding linkage
(i) The linked genes are located on the same chromosome.
(ii) Crossing over between linked genes is maximum.
(iii) The linkage can be broken by crossing over.
(iv) Linkage is against Mendel's law of segregation.

A

(i) and (iii) are correct

B

(i) and (ii) are correct

C

(ii), (iii) and (iv) are correct

D

(i), (iii) and (iv) are correct

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the statements about linkage, we will evaluate each statement one by one. ### Step-by-Step Solution: 1. **Evaluate Statement (i)**: "The linked genes are located on the same chromosome." - This statement is **correct**. Linked genes are indeed located on the same chromosome. They can be tightly or loosely linked depending on their physical distance from each other on that chromosome. **Hint**: Remember that linkage refers to genes that are physically close to each other on the same chromosome. 2. **Evaluate Statement (ii)**: "Crossing over between linked genes is maximum." - This statement is **incorrect**. The frequency of crossing over between linked genes is actually lower compared to unlinked genes. Linked genes tend to be inherited together, and crossing over occurs less frequently between them. **Hint**: Consider how the proximity of genes on a chromosome affects crossing over. 3. **Evaluate Statement (iii)**: "The linkage can be broken by crossing over." - This statement is **correct**. If linked genes are sufficiently far apart, crossing over can separate them, thereby breaking the linkage. **Hint**: Think about how crossing over can shuffle genetic material between homologous chromosomes. 4. **Evaluate Statement (iv)**: "Linkage is against Mendel's law of segregation." - This statement is **incorrect**. Linkage does not contradict Mendel's law of segregation; rather, it is more relevant to Mendel's law of independent assortment. The law of segregation states that alleles segregate independently during gamete formation, which still holds true even with linked genes. **Hint**: Recall the difference between Mendel's laws of segregation and independent assortment. ### Conclusion: Based on the evaluations: - Statement (i) is correct. - Statement (ii) is incorrect. - Statement (iii) is correct. - Statement (iv) is incorrect. Thus, the correct statements are **(i) and (iii)**. ### Final Answer: The correct answer is that **only the first and third statements are correct**.
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