Point out the one which does not justify active absorption of minerals ?

Options

A. Cations and anions are often absoebed at different rates
B. Absorption of different ions is highly selective
C. absorption is accompanied by increase in the rate of respiration
D. Absorption is the movement of substances from higher concentration to their lower concentration

Answer

To solve the question regarding which statement does not justify active absorption of minerals, we can follow these steps:

### Step 1: Understand Active Absorption
Active absorption of minerals refers to the process where plants take up minerals from the soil against their concentration gradient, which requires energy. This process involves both cations and anions.

**Hint:** Remember that active absorption requires energy and occurs against the concentration gradient.

### Step 2: Identify Characteristics of Active Absorption
1. **Selective Absorption**: Active absorption is highly selective, meaning that plants can absorb specific ions preferentially.

**Hint:** Think about how plants need certain nutrients more than others.

2. **Increased Respiration**: Active absorption is associated with an increase in the rate of respiration in plant cells, as energy is needed for the absorption process.

**Hint:** Consider how energy production in cells is linked to the uptake of nutrients.

3. **Movement Against Concentration Gradient**: Active absorption moves substances from an area of lower concentration to an area of higher concentration.

**Hint:** This is a key feature of active transport.

### Step 3: Identify the Incorrect Statement
The question asks for the statement that does not justify active absorption. The statement that suggests absorption occurs from higher concentration to lower concentration contradicts the principle of active absorption, as this describes passive transport, not active transport.

**Hint:** Look for the statement that describes a process that does not require energy.

### Step 4: Conclusion
The statement that does not justify active absorption of minerals is the one that states absorption is the movement of substances from higher concentration to lower concentration.

**Final Answer:** The correct answer is option 4, which does not justify active absorption of minerals.