1. Sunlight: Plants capture sunlight using chlorophyll, a green pigment found in their leaves. This energy from sunlight is essential for the process of photosynthesis.

2. Carbon Dioxide: Plants absorb carbon dioxide from the air through tiny openings called stomata on their leaves. Carbon dioxide is one of the raw materials used in photosynthesis.

3. Water: Plants absorb water from the soil through their roots. Water is another raw material needed for photosynthesis, and it also helps transport nutrients throughout the plant.

4. Minerals: Plants absorb minerals from the soil through their roots. These minerals, such as nitrogen, phosphorus, and potassium, are essential for various plant functions, including the production of starch.

The Process of Starch Production:

Photosynthesis is the process where plants convert light energy into chemical energy stored in the form of glucose. This glucose is then used to build complex carbohydrates, including starch, which serves as the plant's long-term energy reserve.

In short, plants need sunlight, carbon dioxide, water, and minerals to make starch through photosynthesis.