Define photosynthesis, respiration, the levels of ecological organization, the two major parts of the environment, and state the primary formation of sulfur dioxide.

Here are the solutions to your questions:

QUESTION 1
Define:

• (i) Photosynthesis: The process by which green plants, algae, and some bacteria convert light energy into chemical energy, producing glucose (food) and oxygen from carbon dioxide and water.
• (ii) Respiration: The process by which living organisms break down glucose to release energy for metabolic activities, typically consuming oxygen and producing carbon dioxide and water.

QUESTION 2
The levels of ecological organization from smallest to largest are:

1. Individual organism
2. Population
3. Community
4. Ecosystem
5. Biosphere

QUESTION 3
The two major parts of the environment are:

• (i) Biotic factors (living components)
• (ii) Abiotic factors (non-living components)

QUESTION 4
Sulphur dioxide ($\text{SO}_2$) is primarily formed when sulphur-containing fuels such as coal and oil are burned. It can also be released naturally during volcanic eruptions. The chemical reaction for its formation from sulphur and oxygen is:

$$\text{S} + \text{O}_2 \to \text{SO}_2$$