AP BIOLOGY

Detailed explanation-1: -Ethylene is a plant hormone that stimulates the ripening of fruit and inhibits plant growth. It also stimulates senescence of flowers and leaves. It is present in fruits that are ripening, nodes of stems and senescent leaves.

Detailed explanation-2: -Abscisic acid (ABA) and ethylene are the major regulators of ripening and senescence in both dry and fleshy fruits, as demonstrated by numerous ripening-defective mutants, effects of exogenous hormone application, and transcriptome analyses.

Detailed explanation-3: -Ethylene is a gas and is known as the “fruit-ripening hormone.” Every fruit has a certain level of ethylene production throughout its lifecycle. However, in some fruits, ethylene levels shoot up when the fruit starts ripening.

Detailed explanation-4: -Ethylene and Auxin Hormonal coordination is an important aspect, which regulates leaf growth processes. Auxin induces ethylene production, and many effects of exogenous auxins are, in fact, ethylene responses (Abeles et al., 1992).