Assertion (A): A karyotype of 45 with X0 is the key genetic diagnostic point incase of an individual suffering from the Turner's syndrome.
Reason ( R): It is caused due to the presence of an additional copy of the chromosome number 21.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and Rare true but is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true

Explanation

To solve the question, we need to analyze both the Assertion (A) and the Reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states that a karyotype of 45 with X0 is the key genetic diagnostic point in case of an individual suffering from Turner syndrome.

- Turner syndrome is a condition that occurs in females when one of the X chromosomes is missing or partially missing.
- A normal female has two X chromosomes (XX), which gives a total of 46 chromosomes (2n = 46).
- In Turner syndrome, the karyotype is 45, which indicates that one X chromosome is missing (X0).
- Therefore, the assertion is correct.

### Step 2: Analyze the Reason (R)
The reason states that Turner syndrome is caused due to the presence of an additional copy of chromosome number 21.

- This statement is incorrect. Turner syndrome is not caused by an additional chromosome; rather, it is due to the absence of one X chromosome.
- The condition associated with an additional copy of chromosome 21 is known as Down syndrome, not Turner syndrome.
- Therefore, the reason is false.

### Step 3: Conclusion
Since the assertion is true and the reason is false, we conclude that the correct answer is that the assertion is correct while the reason is incorrect.

### Final Answer
The correct option is that the assertion is correct and the reason is wrong.

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