The arrangement of the nuclei in a normal embryo sac in the dicot

Options

A. 3+2+3
B. 2+3+3
C. 3+3+2
D. 2+4+2

Answer

To describe the arrangement of the nuclei in a normal embryo sac in dicots, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of the Embryo Sac**:
- The embryo sac in dicots is a structure that develops within the ovule and contains the female gametes. It is typically seven-celled and eight-nucleate.

2. **Identifying the Components**:
- The embryo sac consists of three main types of cells:
- **Antipodal Cells**: These are located at the opposite end of the embryo sac from the micropyle.
- **Polar Nuclei**: These are located in the center of the embryo sac.
- **Egg Apparatus**: This includes the egg cell and two synergids, located near the micropyle.

3. **Counting the Nuclei**:
- **Antipodal Cells**: There are three antipodal cells, each containing one nucleus.
- **Polar Nuclei**: There are two polar nuclei located in the central cell.
- **Egg Cell**: There is one egg cell that contains one nucleus.
- **Synergids**: There are two synergids, each containing one nucleus.

4. **Summarizing the Arrangement**:
- The total arrangement of nuclei can be summarized as follows:
- Antipodal Cells: 3 nuclei
- Polar Nuclei: 2 nuclei
- Egg Cell: 1 nucleus
- Synergids: 2 nuclei
- Therefore, the total arrangement of nuclei in a normal embryo sac in dicots is 3 (antipodal) + 2 (polar) + 3 (synergids and egg) = 8 nuclei.

5. **Final Answer**:
- The arrangement of the nuclei in a normal embryo sac in dicots is 3 antipodal cells, 2 polar nuclei, and 3 cells in the egg apparatus (1 egg cell + 2 synergids).