Question

The plant hormone controlling fruit ripening is
A)IAA
B)GA
C)ABA
D)Ethylene

Answer 1

Ripening of fruit is defined as the process that causes them to become less green, softer and also more palatable. Ripening of fruit also causes an increase in acidity of the fruit.

Complete answer:
Ripening of fruits is brought about by the help of plant hormones. Plant hormones are signal molecules that are produced in low amounts in the plants and control different plant growth and developmental processes. Plant hormones are of five major kinds- auxin, cytokinin, abscisic acid, ethylene and gibberellin and each of them are known to carry out different processes in plants. Abscisic acid(ABA) is a plant hormone that inhibits growth of plants by preventing seed germination. Auxin also known as indole acetic acid (IAA) is a plant hormone that helps in plant growth by causing enlargement of cells, formation of bud and root initiation.

Cytokinin also helps in plant growth by inducing cell division and formation of shoot. Ethylene is a gaseous hormone that prevents cell elongation and swelling of the stem. They are also responsible for ripening of the fruits. Gibberellin(GA) causes increase in seed germination and also promotes cell elongation.

Hence, the correct answer is option (D)

Note: Plant hormones thus carry out important functions in plants and any abnormalities in their concentration can bring about unwanted changes in plants. Apart from the five major plant hormones there are a few others which also affect developmental processes, they are-jasmonate, brassinosteroid, strigolactones, polyamines, karrikins, etc.