Cytokinins cause delay in senescence (Richmond-Lang effect). Senescence is the phenomenon in which the mature leaves lose chlorophyll, turn yellow and fall off.

Correct Option: C

Cytokinins cause delay in senescence (Richmond-Lang effect). Senescence is the phenomenon in which the mature leaves lose chlorophyll, turn yellow and fall off.

Ethylene acts physiologically as a hormone in plants. It stimulates the ripening of fruit, the opening of flowers, and the abscission (or shedding) of leaves. Its biosynthesis starts from methionine with 1-aminocyclopropane-1-carboxylic acid (ACC) as a key intermediate.

Correct Option: D

Ethylene acts physiologically as a hormone in plants. It stimulates the ripening of fruit, the opening of flowers, and the abscission (or shedding) of leaves. Its biosynthesis starts from methionine with 1-aminocyclopropane-1-carboxylic acid (ACC) as a key intermediate.

Cytokinins are used in tissue culture to induce shooting of the cultural callus.

Correct Option: B

Cytokinins are used in tissue culture to induce shooting of the cultural callus.

Some light sensitive seeds like Lectuca sativa (Lettuce) germinate in complete darkness with the help of Gibberellins which otherwise require specific light conditions.

Correct Option: A

Some light sensitive seeds like Lectuca sativa (Lettuce) germinate in complete darkness with the help of Gibberellins which otherwise require specific light conditions.

Chailakhyan (1936) a Russian investigator who researched on photoperiodism proposed the term ‘florigen’. According to him ‘Florigen Complex’, the true flowering hormone includes two group of substances formed in leaves (i) gibberellins which are necessary for the formation and growth of stem and (ii) anthesins which are necessary for flower formation. Acting together they form the substance named ‘florigen’.

Correct Option: C

Chailakhyan (1936) a Russian investigator who researched on photoperiodism proposed the term ‘florigen’. According to him ‘Florigen Complex’, the true flowering hormone includes two group of substances formed in leaves (i) gibberellins which are necessary for the formation and growth of stem and (ii) anthesins which are necessary for flower formation. Acting together they form the substance named ‘florigen’.