A common characteristic feature of plant sieve tube cells and most of mammalian erythrocytes is

Options

A. absence of mitochondria
B. presence of cell wall
C. presence of haemoglobin
D. absence of nucleus

Answer

To solve the question regarding the common characteristic feature of plant sieve tube cells and most mammalian erythrocytes, we will analyze the options provided and determine which one is applicable to both cell types.

### Step-by-Step Solution:

1. **Understanding Erythrocytes**:
- Erythrocytes, also known as red blood cells (RBCs), are responsible for transporting oxygen throughout the body. They contain hemoglobin, which binds to oxygen.

**Hint**: Recall the function of erythrocytes and their key components.

2. **Understanding Sieve Tube Cells**:
- Sieve tube cells are part of the phloem in plants and are responsible for the transport of nutrients, particularly sugars. Unlike erythrocytes, sieve tube cells do not contain hemoglobin.

**Hint**: Identify the role of sieve tube cells in plants and their structural characteristics.

3. **Analyzing the Options**:
- **Absence of Mitochondria**:
- While mature mammalian erythrocytes lack mitochondria, sieve tube cells may have mitochondria to produce energy. Therefore, this is not a common feature.
- **Presence of Cell Wall**:
- Sieve tube cells have a cell wall, while erythrocytes do not. Thus, this option is also not common.
- **Absence of Hemoglobin**:
- Erythrocytes contain hemoglobin, while sieve tube cells do not. Hence, this is not a common feature.
- **Absence of Nucleus**:
- Mature mammalian erythrocytes lack a nucleus. Sieve tube cells also lose their nuclei at maturity. This is a common feature between the two.

**Hint**: Compare the structural features of both cell types to identify similarities.

4. **Conclusion**:
- The common characteristic feature of plant sieve tube cells and most mammalian erythrocytes is the **absence of nucleus** at maturity.

### Final Answer:
The common characteristic feature of plant sieve tube cells and most mammalian erythrocytes is the **absence of nucleus**.