Length of Y-chromosome is

Options

A. 2.0 `mu`
B. 3.0 `mu`
C. 4.0 `mu`
D. 5.0 `mu`

Answer

To determine the length of the Y-chromosome, we can follow these steps:

### Step 1: Understand the Options
The question provides four options for the length of the Y-chromosome: 2.0 mu, 3.0 mu, 4.0 mu, and 5.0 mu.

### Step 2: Know the Length of the Y-Chromosome
The Y-chromosome is known to contain approximately 59,373,566 base pairs.

### Step 3: Convert Base Pairs to Millimeters
The length of the Y-chromosome can be approximated to be around 20 millimeters.

### Step 4: Convert Millimeters to Mapped Units (mu)
In genetics, 1 mapped unit (mu) is equivalent to 1% recombination frequency, which corresponds to a distance of about 1 million base pairs. Given that the Y-chromosome has a length of approximately 20 millimeters, we can convert this to mu.

### Step 5: Calculate the Length in mu
Since the Y-chromosome has about 59 million base pairs, we can calculate its length in mu:
- 1 mu = 1 million base pairs
- Therefore, the length of the Y-chromosome in mu = 59.37 million base pairs / 1 million base pairs = 59.37 mu.

### Step 6: Identify the Correct Option
From the options given (2.0 mu, 3.0 mu, 4.0 mu, 5.0 mu), the closest and most reasonable estimate for the length of the Y-chromosome is 2.0 mu.

### Conclusion
Thus, the correct answer is **2.0 mu**.

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