Which abiotic factor is not essential for early growth of the plant but growth is sustained only in its presence?

Options

A. a) Water
B. b) Oxygen
C. c) Nutrients
D. d) Light

Answer

**Step-by-Step Solution:**

1. **Understanding Abiotic Factors**: Begin by defining abiotic factors. Abiotic factors are non-living components of the environment that affect living organisms, particularly plants. They include elements such as water, oxygen, nutrients, and light.

2. **Analyzing the Options**: The question provides four options: water, oxygen, nutrients, and light. We need to determine which of these is not essential for the early growth of a plant but is necessary for sustaining growth later.

3. **Evaluating Water**: Water is crucial for plant growth from the very beginning, including during the germination of seeds. It is essential for various physiological processes, including nutrient transport and photosynthesis.

4. **Evaluating Oxygen**: Oxygen is vital for respiration, which is necessary for energy production in plants. Like water, oxygen is also essential during the early growth stages.

5. **Evaluating Nutrients**: Nutrients are necessary for the development of plants. They are absorbed from the soil and are critical for various metabolic processes. Thus, nutrients are also essential from the early stages of plant growth.

6. **Evaluating Light**: Light is primarily required for photosynthesis, which occurs after the plant has developed beyond the seed stage. In the early growth stages, particularly during germination, plants do not rely on light for energy, as they utilize stored nutrients from the seed.

7. **Conclusion**: Based on the analysis, light is the abiotic factor that is not essential for the early growth of the plant but is necessary for sustaining growth later on. Therefore, the correct answer is **light**.

**Final Answer**: The abiotic factor that is not essential for early growth of the plant but growth is sustained only in its presence is **light**.

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