NEET BIOLOGY

Detailed explanation-1: -A cytokinin plant growth hormone kinetin (Kn) retards senescence in plants and delays ageing in human cells in culture.

Detailed explanation-2: -The plant hormone that retards senescence in plants and delays ageing is known as cytokinin or kinetin.

Detailed explanation-3: -Cytokinin was discovered by Miller when he was working on tobacco pith culture. The term cytokinin was given by Letham. Cytokinins are plant growth regulators that produce anti-senescence effects on some plant parts.

Detailed explanation-4: -Cytokinins are plant-specific chemical messengers (hormones) that play a central role in the regulation of the plant cell cycle and numerous developmental processes. Cytokinins were discovered by F Skoog, C Miller, and co-workers during the 1950s as factors that promote cell division (cytokinesis).

Detailed explanation-5: -Cytokinin is known to be instrumental in inhibiting auxin transport [6], [7], and auxin inhibition has been linked to increased resistance to infection by many pathogens, including Pto [13].