What is an essential element ?

Options

A. (a) An element present in the soil.
B. (b) An element present in the plant.
C. (c) An element that improves growth of plant.
D. (d) An element without which a plant will not grow and complete its life cycle.

Answer

### Step-by-Step Solution:

1. **Definition of Essential Elements**:
- Essential elements are specific chemical elements that are necessary for the growth and development of plants and other organisms.

2. **Presence in Soil**:
- These elements are typically found in the soil, where plants can absorb them through their roots. This indicates that essential elements must be available in the environment for plants to utilize.

3. **Presence in Plants**:
- Essential elements are also present within the plant tissues. They play crucial roles in various physiological and biochemical processes, contributing to the overall health of the plant.

4. **Role in Growth**:
- Essential elements improve the growth of plants. They are involved in processes such as photosynthesis, respiration, and nutrient transport, which are vital for the plant's development.

5. **Life Cycle Completion**:
- An essential element is one that is absolutely necessary for a plant to grow and complete its life cycle. Without these elements, a plant cannot survive, reproduce, or carry out its biological functions.

6. **Conclusion**:
- The universal definition of essential elements can be summarized as those elements without which a plant will not grow and complete its life cycle. Examples of essential elements include carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, which together make up a significant portion of the plant's body.