The amount of starch in a germinating seed decreases because the starch is used up

Step 1: Analyze the question The question asks why the starch stored in a germinating seed decreases over time. So we need to know what happens to the stored food during germination.

Step 2: The concept Seeds store food as starch in the cotyledons or endosperm. During germination:

1. The seed absorbs water, which activates enzymes such as amylase.
2. Amylase breaks down insoluble starch into soluble sugars (maltose, then glucose).
3. The glucose is then used in two main ways: • Respiration, which releases energy for growth processes. • Building new cells, where glucose is converted into materials such as cellulose, proteins and protoplasm for the growing radicle and plumule.

Step 3: Evaluate the options

• A. For respiration and building up of cells. Correct. It covers both uses of the starch, which are energy release and growth.
• B. To build cellulose cell wall. This is only part of the story. Cellulose is one product, and it leaves out the energy supply from respiration.
• C. To develop meristematic tissues. Too narrow. Meristems are only one of the tissues being built.
• D. For the production of enzymes. Enzymes are made mainly from proteins, not starch. Starch is the substrate that enzymes act on.

Step 4: Answer The correct answer is A. Starch is digested to glucose, which supplies energy through respiration and provides raw materials for building new cells.

Exam tip: In germination questions, remember the chain: water → enzymes activate → starch becomes sugar → energy (respiration) + growth (new cells). When one option covers both energy and growth, it is usually the best choice over options that name only one specific use.