BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Cytokinins are plant hormones which promotes cytokinesis or cell division. It also helps in opening of stomata, delaying ageing in leaves, etc.

Detailed explanation-2: -Cytokinin promotes nuclear localization of a transcription factor to activate cell division. Organ morphogenesis in plants is largely determined by the rate and patterns of cell division (1) occurring primarily in meristematic tissues such as the shoot and root meristems, and vascular cambium (2).

Detailed explanation-3: -Cytokinins promote cell division, cell growth and differentiation along with auxin. Ethylene is responsible for fruit ripening. Abscisic acid helps the plant to sustain in adverse conditions. Gibberellins enable the plants to grow taller.

Detailed explanation-4: -So, the correct answer is ‘Cytokinin’.

Detailed explanation-5: -Cytokinins are the plant growth hormones that regulate the cell division in root and shoot of the plant both in vivo and in vitro.