Go through the following points regarding diffusion
I. It is a passive and slow process
II. It is an active and fast process
III. It needs ATP
IV. It does not need energy
V. It occurs against the concentration gradient
VI. Molecules move in a random manner, the net result being sụbstances moving from region of higher concentration to region of lower concentration

Options

A. I, III and V are correct
B. Il and V are correct
C. All are correct except III
D. All are correct except II, III and V.

Answer

To analyze the statements regarding diffusion, we will evaluate each point one by one based on the principles of diffusion.

### Step-by-Step Solution:

1. **Statement I: It is a passive and slow process.**
- **Evaluation:** This statement is correct. Diffusion is indeed a passive process, meaning it does not require energy input (ATP). It is generally considered a slow process compared to other transport mechanisms.

2. **Statement II: It is an active and fast process.**
- **Evaluation:** This statement is incorrect. Diffusion is not an active process; it does not require energy (ATP) and occurs from a region of higher concentration to a region of lower concentration.

3. **Statement III: It needs ATP.**
- **Evaluation:** This statement is incorrect. Diffusion does not require ATP or any other form of energy, as it is a passive process.

4. **Statement IV: It does not need energy.**
- **Evaluation:** This statement is correct. As mentioned, diffusion is a passive process and does not require energy input.

5. **Statement V: It occurs against the concentration gradient.**
- **Evaluation:** This statement is incorrect. Diffusion occurs along the concentration gradient, meaning substances move from areas of higher concentration to areas of lower concentration.

6. **Statement VI: Molecules move in a random manner, the net result being substances moving from regions of higher concentration to regions of lower concentration.**
- **Evaluation:** This statement is correct. Molecules do move randomly, and the overall effect is the movement from high to low concentration.

### Summary of Correct Statements:
- Correct statements: I, IV, VI
- Incorrect statements: II, III, V

Thus, the correct options regarding diffusion are statements I, IV, and VI.