AP BIOLOGY

Detailed explanation-1: -Gibberellins are a group of phytohormones that regulate plant developmental processes such as seed germination, flowering, stem elongation, breaking dormancy, sex expression, and leaf/fruit senescence (Hedden and Phillips, 2000).

Detailed explanation-2: -GA stimulates the seed germination whereas, ABA is involved in the establishment and maintenance of dormancy. GA exerts its influence in two manners, first by increasing the growth potential of embryo and second by inducing hydrolytic enzymes.

Detailed explanation-3: -Gibberellins‐mediated control of seed dormancy release and germination. A high level of gibberellins (GA) is needed for the counteraction of ABA activity in seeds. GA promotes seed dormancy release and radical protrusion during seed germination.

Detailed explanation-4: -Fruit growth depends on highly coordinated hormonal activities. The phytohormone gibberellin (GA) promotes growth by triggering degradation of the growth-repressing DELLA proteins; however, the extent to which such proteins contribute to GA-mediated fruit development remains to be clarified.