'Climacteric' is

• a phenomenon related to fruit ripening

• the condition of a plant when all its fruits are almost ripe

• the condition of a plant when most of its leaves have turned yellow

• none of the above

Ethylene is a

• gaseous hormone

• gaseous enzyme

• liquid-gas mixture

• solid hormone

213.

The plants respond to photoperiods due to the presence of :

• enzymes

• stomata

• phytochromes

• phytohormones

Which chemical is used for induction of polyploidy?

• Cytokinin

• Nitrous acid

• Colchicine

• IAA

Tendrils exhibit/twining of tendrils is due to

• thigmotropism

• seismonasty

• heliotropism

• diageotropism

Flowering dependent on cold treatment is

• cryotherapy

• cryogenics

• cryoscopy

• vernalisation

A substance that induces dormancy of seed is

• ABA

• GA

• thio-urea

• cytokinin

Which of the following is called stress hormone?

• Abscisic acid

• Auxin

• Cytokinin

• Gibberellic acid

Vascular tissue in higher plants develop from which of the following

• Procambium 

• Protoderm

• Periblem

• Cortex

The discovery of gibberellins is related with one of the following

• blast disease of rice

• rust disease of wheat

• bakane disease of rice

• early blight disease of potato