Direction: In the following questions a statement of assertion (A) is...
Colour blindness is X-linked sex inheritance. The frequency of red-green colour blindness is many times higher in males than that in the females because males have only one X chromosomes therefore they develop colour blindness when their sole X- chromosome has the allele for it. Thus, males are more prone to colour blindness while females are carriers. For becoming colour blind, the female must have the allele for it in both her X-chromosomes and if only one X-chromosome of female possess allele for colour blind character she becomes the carrier for this characteristic.
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Direction: In the following questions a statement of assertion (A) is...
**Explanation:**
The correct answer is option (d) Assertion (A) is false but reason (R) is true.
**Explanation:**
**Assertion (A):** The frequency of red-green colour blindness is many times higher in females than that in males.
**Reason (R):** In females if only one X-chromosome of female possess allele for colour blind character she becomes the colour blind.
Let's break down the given information and analyze it step by step:
1. Red-green color blindness is an X-linked recessive disorder. This means that the gene responsible for color blindness is located on the X chromosome.
2. In males, only one X chromosome is present, so if it carries the allele for color blindness, the male will be color blind.
3. In females, two X chromosomes are present. For a female to be color blind, both of her X chromosomes must carry the allele for color blindness.
4. If only one X chromosome in a female carries the allele for color blindness, she will be a carrier of the disorder but not color blind herself.
5. The reason for the higher frequency of red-green color blindness in males is that they have only one X chromosome, so if it carries the allele for color blindness, they will be color blind.
6. On the other hand, females have two X chromosomes, and both chromosomes would need to carry the allele for color blindness for the female to be color blind.
7. Since males have a higher chance of inheriting the color blindness allele due to their single X chromosome, the frequency of red-green color blindness is higher in males compared to females.
From the given information, it is clear that the assertion (A) is false because the frequency of red-green color blindness is higher in males, not females. However, the reason (R) is true as it explains the genetic basis for the higher frequency of color blindness in males.
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