Number of chromosome groups at each equatorial plate of metaphase I of a plant having 2n = 60 chromosomes, will be

Options

A. 60
B. 120
C. 180
D. 30

Answer

To determine the number of chromosome groups at each equatorial plate of metaphase I for a plant with a diploid number (2n) of 60 chromosomes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Diploid Number**:
- The diploid number (2n) indicates the total number of chromosomes in a somatic cell. In this case, 2n = 60 means there are 60 chromosomes in total.

2. **Calculating the Haploid Number**:
- The haploid number (n) is half of the diploid number. Therefore, n = 60/2 = 30. This means there are 30 chromosomes in a gamete.

3. **Meiosis and Metaphase I**:
- During meiosis, specifically in metaphase I, homologous chromosomes pair up. Each pair consists of two homologous chromosomes.

4. **Arrangement of Chromosomes at the Equatorial Plate**:
- At metaphase I, the homologous chromosome pairs align at the equatorial plate. Since there are 30 pairs of homologous chromosomes, they will line up at the equatorial plate.

5. **Counting the Groups**:
- Each pair of homologous chromosomes represents a group. Therefore, if there are 30 pairs, there will be 30 groups of chromosomes at the equatorial plate during metaphase I.

### Final Answer:
The number of chromosome groups at each equatorial plate of metaphase I of a plant having 2n = 60 chromosomes will be **30**.

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