Which method is responsible for most of the absorption in higher plants?

Options

A. Active absorption
B. Passive absorption
C. Osmotic absorption
D. Non - osmotic absorption.

Answer

### Step-by-Step Solution:

1. **Understanding Plant Absorption**:
- Plants absorb water and nutrients primarily through their roots. The outermost layer of the root is called the epidermis.

2. **Role of Root Hairs**:
- The root hairs are unicellular outgrowths from the epidermis of the root. They significantly increase the surface area for absorption and are crucial for the absorption process.

3. **Types of Absorption**:
- There are two main methods of absorption in plants: Active Absorption and Passive Absorption.

4. **Active Absorption**:
- Active absorption requires energy in the form of ATP (adenosine triphosphate). This method is used when substances need to be moved against their concentration gradient (from a region of lower concentration to a region of higher concentration).

5. **Passive Absorption**:
- Passive absorption does not require energy. It occurs through processes like diffusion and osmosis, where substances move along their concentration gradient (from a region of higher concentration to a region of lower concentration).

6. **Comparison of Active and Passive Absorption**:
- Active absorption is faster but less common, while passive absorption is slower but accounts for about 98% of the absorption in higher plants.

7. **Conclusion**:
- Given that passive absorption is the predominant method used by higher plants for absorbing water and nutrients, the answer to the question is that **Passive Absorption** is responsible for most of the absorption in higher plants.