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

During germination, the embryo in a seed grows into a new plant. In order for the embryo to grow, it needs energy and building materials. The energy is obtained through respiration, which breaks down stored food molecules such as starch into smaller molecules that can be used by the plant. Therefore, the starch in the seed is used up as a source of energy for respiration and for building new cells as the plant grows. This is why the amount of starch in a germinating seed decreases. The other options, building cellulose cell wall, developing meristematic tissues, and producing enzymes, may require energy and building materials, but do not directly lead to the breakdown of starch.