Which of the following factor affect diffusion rate?

Options

A. Gradient of concentration
B. Temperature and light
C. Permeability of the membranes
D. Both (1) and (3)

Answer

To determine which factors affect the rate of diffusion, we can analyze the options provided and the principles of diffusion. Here’s a step-by-step solution:

### Step 1: Understand the Concept of Diffusion
Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. The rate of diffusion is influenced by several factors.

### Step 2: Identify the Factors Affecting Diffusion
The main factors that affect the rate of diffusion include:
1. **Concentration Gradient**: A higher difference in concentration between two areas increases the rate of diffusion.
2. **Permeability of Membranes**: The ability of substances to pass through a membrane affects diffusion. More permeable membranes allow faster diffusion.
3. **Temperature**: Higher temperatures increase the kinetic energy of molecules, leading to faster movement and increased diffusion rates.
4. **Pressure**: Increased pressure can also enhance the rate of diffusion, particularly in gases.

### Step 3: Analyze the Options
Now, let's look at the options provided in the question:
- **Option A**: Gradient of concentration
- **Option B**: Temperature and light
- **Option C**: Permeability of membranes
- **Option D**: Both A and C

### Step 4: Evaluate Each Option
- **Option A** (Gradient of concentration): This is a correct factor affecting diffusion.
- **Option B** (Temperature and light): While temperature is a factor, light does not directly affect diffusion rates, making this option incorrect.
- **Option C** (Permeability of membranes): This is also a correct factor affecting diffusion.
- **Option D** (Both A and C): Since both the concentration gradient and permeability of membranes are correct factors, this option is correct.

### Conclusion
The correct answer is **Option D**, as both the gradient of concentration (Option A) and permeability of membranes (Option C) affect the rate of diffusion.

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