In angiosperm phloem

Options

A. Both the sieve țube elements and companion cells have nuclei
B. Sieve tube elements have nuclei but companion cells do not
C. The companion cells have nuclei but the sieve tube elements do not
D. Neither the companion cells nor sieve tube elements have nuclei

Answer

### Step-by-Step Solution:

1. **Understanding Phloem Composition**:
- Phloem is a complex tissue in angiosperms (flowering plants) that is responsible for the transport of nutrients, particularly sugars produced during photosynthesis.

2. **Identifying the Components of Phloem**:
- Phloem consists of four main components:
- Sieve tube elements (also referred to as sieve tubes)
- Companion cells
- Phloem fibers
- Phloem parenchyma

3. **Focusing on Sieve Tube Elements and Companion Cells**:
- Sieve tube elements are specialized cells that facilitate the movement of sugars. They are unique because they lack a nucleus (are enucleated).
- Companion cells are closely associated with sieve tube elements and contain a nucleus. They play a crucial role in supporting the sieve tube elements by providing metabolic functions.

4. **Relationship Between Sieve Tube Elements and Companion Cells**:
- Sieve tube elements and companion cells originate from the same mother cell during development, which is why they are often referred to as sister cells.
- The companion cell’s nucleus controls the functions of the sieve tube element.

5. **Evaluating the Statements**:
- The question likely presents multiple statements about the presence of nuclei in these cells.
- The correct statement is that the companion cell has a nucleus, while the sieve tube element does not.

6. **Conclusion**:
- Based on the above analysis, the correct answer to the question regarding the presence of nuclei in angiosperm phloem is that the companion cell has a nucleus, but the sieve tube element does not.

### Final Answer:
- The correct option is **Option 3**: The companion cell has a nucleus, but the sieve tube element does not have a nucleus.