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 hemoglobin
D. absence of nucleus.

Explanation

To answer the question about the common characteristic feature of plant sieve tube cells and most mammalian erythrocytes, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Cell Types:**
- Plant sieve tube cells are part of the phloem, which is responsible for the transport of nutrients (mainly sugars) in plants.
- Mammalian erythrocytes (red blood cells) are involved in the transport of gases, particularly oxygen and carbon dioxide, in the bloodstream.

2. **Examine Key Features:**
- Sieve tube cells are specialized cells that lack certain organelles to facilitate their function in nutrient transport.
- Mammalian erythrocytes also undergo a process during maturation where they lose their nucleus.

3. **Compare the Characteristics:**
- Both sieve tube cells and mature mammalian erythrocytes lack a nucleus. This is a significant feature that allows for more space for their respective functions (nutrient transport in sieve tubes and gas transport in erythrocytes).

4. **Eliminate Other Options:**
- Sieve tube cells do not have mitochondria, while mammalian erythrocytes do have mitochondria (though they do not use them for respiration).
- Sieve tube cells have a cell wall, while erythrocytes do not.
- Hemoglobin is present in erythrocytes but not in sieve tube cells.

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

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

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