Question

During seed germination, its stored food is mobilized by
A. Ethylene
B. Cytokinin
C. ABA
D. Gibberellin

Answer 1

Hint: Seed germination refers to the process of sprouting of the seed. The fertilized ovary makes a zygote or embryo that matures to form identical plants as parents. This is called germination. The developing embryo consists of stored food that provides its nourishment during the growth phase. The stored food moves from one place to another growing place in germinating seed with the help of plant hormone that regulates stem elongation, seed dormancy, and germination.

Complete answer: Seed germination is the process of maturation of the embryo enclosed in a seed. Germination is an important and sensitive step that results in the formation of a new individual plant. This process happens only under suitable conditions. The seed remains dormant for a certain period until the favorable sprouting conditions arrive. In this dormant period, the seed utilizes the stored food inside it. On stimulation by environmental factors when a suitable season arrives, the seed starts to grow. The growing seed needs nutrition to make a plant. As the initial stages have no developed roots, the growing seed provides nourishment to the growing plant through stored food. This stored food is transported to the growing parts with the help of a plant hormone. This plant hormone is involved in seed germination initiation. Also, it regulates elongation of the stem, flower development, fruit and leaf senescence, etc. This hormone is called gibberellin. The gibberellin is involved in the regulation of various plant developmental stages. It stimulates the aleurone cells present in the aleurone layer situated around the endosperm. The activation of aleurone cells releases an enzyme that breaks down the stored food and mobilizes it towards the maturing parts.
Therefore, the right answer is option D, i.e., Gibberellin.

Note: Ethylene is a plant growth regulator that is used to stimulate enhanced fruit ripening. Also, ethylene acts as a determining factor for the sex of plants. Cytokinins are a class of hormones that regulates the plant cell cycle. ABA or abscisic acid is a plant hormone that regulates the stomatal opening and protects plant cells from dehydration. The gibberellins induce the starch hydrolysis that is stored in the seed. This results in the breakdown of food and its mobilization.