Find the appropriate option which justifies all these statements.
i. Protect the cell by acting a barrier.
ii. Regulates the transport of substances in and out of the cell.
iii. Receives chemical messengers from other cells.
iv. Acts as a receptor.
v. Cell mobility , secretions , and absorptions of substances.

Options

A. The nuclear membrane
B. Endomembranous system
C. Plasma membrane
D. All of these

Answer

To solve the question, we need to identify which option best justifies the given statements about cellular functions. Let's analyze each statement step by step:

1. **Protect the cell by acting as a barrier.**
- The cell membrane (plasma membrane) serves as a protective barrier that separates the interior of the cell from the external environment. It maintains the integrity of the cell.

**Hint:** Think about what structures in a cell provide protection and separation from the outside environment.

2. **Regulates the transport of substances in and out of the cell.**
- The plasma membrane is selectively permeable, meaning it regulates what enters and exits the cell. It contains various transport proteins that facilitate the movement of substances.

**Hint:** Consider how cells control the movement of ions, nutrients, and waste products.

3. **Receives chemical messengers from other cells.**
- The plasma membrane contains receptors that can bind to signaling molecules (like hormones or neurotransmitters) from other cells, allowing for communication and response.

**Hint:** Think about how cells communicate with each other through signaling molecules.

4. **Acts as a receptor.**
- The plasma membrane has specific receptor proteins that recognize and bind to particular molecules, triggering a response within the cell.

**Hint:** Reflect on how cells can detect changes in their environment through specific binding sites.

5. **Cell mobility, secretions, and absorptions of substances.**
- The plasma membrane plays a role in cell mobility (through structures like cilia and flagella), secretion (through exocytosis), and absorption (through endocytosis and transport proteins).

**Hint:** Consider the various ways cells interact with their environment and take in or release substances.

After analyzing all the statements, we conclude that the plasma membrane is the structure that justifies all the given functions. Therefore, the correct answer is:

**Answer:** Plasma membrane (Option 3).