Multiple Choice Questions

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Ethylene is a

  • gaseous hormone

  • gaseous enzyme

  • liquid-gas mixture

  • solid hormone


A.

gaseous hormone

Ethylene is thought of as the aging hormone in plants. In addition to causing fruit to ripen, it can cause plants to die. It can be produced when plants are injured, either mechanically or by disease. Ethylene gas is used commercially to ripen tomatoes, bananas, pears, and a few other fruits postharvest


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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


'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


Cork cambium results in the formation of cork which becomes impermeable to water due to the accumulation of

  • resins

  • lignins

  • suberin

  • tannins.


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Avena curvature test is a bioassay for examining the activity of

  • auxins

  • cytokinins

  • gibberellins

  • ethylene.


Gibberellins can promote seed germination because of their influence on

  • rate of cell division

  • production of hydrolyzing enzymes

  • synthesis of abscisic acid

  • absorption of water through hard seed coat


Pruning of plants promotes branching because the axillary buds get sensitized to

  • ethylene

  • gibberellin

  • cytokinin

  • indole acetic acid.


Tendrils exhibit/twining of tendrils is due to

  • thigmotropism

  • seismonasty

  • heliotropism

  • diageotropism


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In a plant organ which is covered by periderm and in which the stomata are absent, some gaseous exchange still takes place through

  • aerenchyma

  • trichornes

  • pneumatophores

  • lenticels.


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