In the hexaploid wheat, the haploid (n) and basic (x) number of chromosomes are :

Options

A. n = 21 and x = 7
B. n = 7 and x = 21
C. n = 21 and x = 21
D. n = 21 and x = 14

Answer

To determine the haploid (n) and basic (x) number of chromosomes in hexaploid wheat, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hexaploidy**:
- Hexaploid means that the organism has six sets of chromosomes. This is denoted as 6N, where N represents the haploid number of chromosomes.

2. **Identifying the Chromosome Number**:
- In hexaploid wheat (Triticum aestivum), the total number of chromosomes is 6N. To find the haploid number (n), we divide the total number of chromosomes by 6.
- Therefore, if we denote the haploid number as n, we have:
\[ n = \frac{6N}{6} = N \]

3. **Determining the Haploid Number (n)**:
- It is established that the haploid number (n) for hexaploid wheat is 7. This means that in a single set of chromosomes, there are 7 different chromosomes.

4. **Understanding the Basic Number (x)**:
- The basic number of chromosomes (x) refers to the number of unique chromosomes in a single set. In the case of hexaploid wheat, the basic number is also equal to the haploid number, which is 7.
- Thus, we can conclude:
\[ x = n = 7 \]

5. **Final Answer**:
- Therefore, in hexaploid wheat, both the haploid number (n) and the basic number (x) of chromosomes are 7.

### Summary:
- **Haploid Number (n)**: 7
- **Basic Number (x)**: 7