Select the incorrect regarding mineral nutrition in plants.

Options

A. Cotyledons store microelements
B. Deficiency of microelements is more common
C. Microelements constitue 10% of dry matter
D. Nernst equation is used to predict whether ion absorption is passive or acitve

Answer

To determine the incorrect statement regarding mineral nutrition in plants, we will evaluate each of the provided statements step by step.

### Step 1: Analyze the first statement
**Statement:** "Cotyledons store micronutrients."
**Analysis:** Cotyledons are the first leaves that appear on a seedling and primarily serve to store food for the developing plant. This food can include micronutrients, which are essential for plant growth.
**Conclusion:** This statement is **correct**.

### Step 2: Analyze the second statement
**Statement:** "Deficiency of micronutrients is more common."
**Analysis:** Micronutrient deficiencies can lead to various plant diseases, such as chlorosis and necrosis. These deficiencies are indeed common, especially in certain soils that lack these essential elements.
**Conclusion:** This statement is **correct**.

### Step 3: Analyze the third statement
**Statement:** "Micronutrients constitute 10 percent of the dry matter."
**Analysis:** Micronutrients are required in very small amounts and typically constitute much less than 10 percent of the dry matter of plants. This statement is misleading as it overestimates the proportion of micronutrients in plant dry matter.
**Conclusion:** This statement is **incorrect**.

### Step 4: Analyze the fourth statement
**Statement:** "Nernst equation is used to predict whether ion absorption is passive or active."
**Analysis:** The Nernst equation relates to electrochemical gradients and can be used to determine the potential difference across a membrane, which helps in understanding whether ion absorption is occurring passively (along the gradient) or actively (against the gradient).
**Conclusion:** This statement is **correct**.

### Final Conclusion
After analyzing all the statements, the incorrect statement is the third one: "Micronutrients constitute 10 percent of the dry matter." Therefore, the answer to the question is option **C**.

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