251.

Which one of the following is a natural growth inhibitor?

• NAA

• ABA

• IAA

• GA

Which one is a short day plant?

• Brassica campestris

• Raphanus sativus

• Glycine max

• Papaver somniferum

Leaf abscission is caused by

• ABA

• cytokinin

• auxin

• gibberellin

The synthetic hormone used as a weedicide is

• Indole 3-acetic acid

• gibberellic acid

• 2, 4- D 

• Indole butyric acid

First natural cytokinin was discovered by :

• Skoog and Miller

• Letham

• Benson and Calvin

• Thimann and Went

Which hormone is responsible for mobilization of storage food during seed germination ?

• Auxin

• Gibberellin

• Cytokinin

• Ethylene

Bud dormancy is induced by

• ABA

• ethylene

• IAA

• gibberellic acid

Induction of flowering by low temperature in plants is

• cryobiology

• vernalization

• phototropism

• pruning

Which of the following plant growth hormone increases the yield of sugar by increasing the length of stem in sugarcane?

• Cytokinin

• Auxin

• Abscisic acid

• Ethylene

• Ethylene

One hormone hastens the maturity period in juvenile conifers, a second hormone controls xylem differentiation while the third increases the tolerance of plants to various stresses and they are respectively-

• Auxin, Gibberellin and Cytokinin

• Gibberellin, Auxin and Cytokinin

• Gibberellin, Auxin and Ethylene

• Gibberellin, Auxin and ABA

• Gibberellin, Auxin and ABA