32 chromosomes are present in the green leaf of Onion. When meiosis takes place to produce gametes after fertilization then, how many chromosomes will be there in triploid nucleus
(a) 32
(b) 16
(c) 48
(d) 9

Options

A. 32
B. 16
C. 48
D. 9

Answer

To solve the problem, we need to follow these steps:

### Step 1: Understand the chromosome number in the onion leaf
The question states that there are 32 chromosomes in the green leaf of onion. This indicates that the onion is diploid (2n), meaning it has two sets of chromosomes.

### Step 2: Determine the haploid number (n)
Since the onion is diploid (2n = 32), we can find the haploid number (n) by dividing the diploid number by 2:
\[ n = \frac{2n}{2} = \frac{32}{2} = 16 \]
Thus, the haploid number (n) is 16.

### Step 3: Understand gamete formation
During meiosis, gametes are formed, which are haploid. Therefore, each gamete will have 16 chromosomes (n = 16).

### Step 4: Understand fertilization and triploid formation
When two gametes fuse during fertilization, a diploid zygote is formed. However, the question asks about a triploid nucleus. A triploid nucleus (3n) means that there are three sets of chromosomes.

### Step 5: Calculate the number of chromosomes in a triploid nucleus
To find the number of chromosomes in a triploid nucleus, we multiply the haploid number (n) by 3:
\[ 3n = 3 \times 16 = 48 \]
Thus, in a triploid nucleus, there will be 48 chromosomes.

### Conclusion
The correct answer is (c) 48.

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