Photosynthesis requires carbon dioxide, water, and sunlight to produce carbohydrates and oxygen. Oxygen is a byproduct, not a raw material.

Explanation:

Photosynthesis:
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy stored in glucose. This process involves the use of certain raw materials and the production of oxygen as a byproduct.

Raw materials required for photosynthesis:
- Carbon dioxide: Carbon dioxide is a gas that is taken in by plants through small openings on their leaves called stomata. It is used during the light-independent reactions of photosynthesis to produce glucose.
- Water: Water is absorbed by plant roots from the soil and transported to the leaves. It is split during the light-dependent reactions of photosynthesis to release oxygen and provide electrons for the production of ATP and NADPH.
- Sunlight: Sunlight is the energy source for photosynthesis. Plants capture sunlight using the pigment chlorophyll, which is located in the chloroplasts of their cells. This light energy is converted into chemical energy during the light-dependent reactions.

Not a raw material for photosynthesis:
- Oxygen: Oxygen is actually a byproduct of photosynthesis. During the light-dependent reactions, water molecules are split to release oxygen as a waste product. This oxygen is then released into the atmosphere, where it can be used by animals and other organisms for respiration.
In conclusion, while carbon dioxide, water, and sunlight are essential raw materials for photosynthesis, oxygen is not a raw material but rather a product of the process.