Which is not true regarding ecosystem?

Options

A. Self sufficient unit
B. Cyclic exchange of materials between living beigns and environment
C. Only requirement is input of enregy
D. Characterized by a major vegetation type

Answer

To determine which statement is not true regarding ecosystems, we will analyze each of the four statements provided:

1. **Self-sufficient unit**: This statement suggests that an ecosystem can function independently without relying on external factors. However, ecosystems are not self-sufficient; they depend on both biotic (living organisms) and abiotic (non-living elements like soil, air, and water) components for their functioning. Therefore, this statement is not true.

2. **Cyclic exchange of materials between the living beings and environment**: This statement is true. Ecosystems are characterized by the cyclic exchange of materials, where nutrients and energy flow between biotic and abiotic components. For example, plants absorb nutrients from the soil, and when they die, their decomposed matter enriches the soil, continuing the cycle.

3. **Only requirement is input of energy**: This statement is misleading. While energy input (primarily from the sun) is crucial for ecosystems, it is not the only requirement. Ecosystems also need nutrients, water, and other abiotic factors to sustain life. Hence, this statement is not entirely accurate.

4. **Characterized by major vegetation style**: This statement is true. Ecosystems can be classified based on their dominant vegetation types, such as forests, grasslands, deserts, etc. The vegetation is influenced by the climate and soil conditions of the area.

After analyzing all four statements, we conclude that the statement that is not true regarding ecosystems is:

**Answer**: Self-sufficient unit.