21.

Senescence as an active development cellular process in the growth and functioning of a flowering plant is indicated in 

• vessel and tracheid differentiation

• leaf abscission

• annual plants

• annual plants

The length of different internodes in a culm of sugarcane is variable because of

• shoot apical meristem

• position of axillary buds

• size of leaf lamina at the node below each internode

• size of leaf lamina at the node below each internode

In leaves of C₄ -plants malic acid synthesis during CO₂ -fixation occurs in

• epidermal cells

• mesophyll cells

• bundle sheath

• bundle sheath

In germinating seeds fatty acids are degraded exclusively in the

• proplastid

• glyoxisomes

• peroxisomes

• peroxisomes

The wavelength of light absorbed by P_r form of phytochrome is

• 640 nm

• 680 nm

• 720 nm

• 720 nm

'Foolish seedling' disease of rice led to the discovery of

• GA

• ABA

• 2, 4-D

• 2, 4-D

Which one of the following pairs, is not correctly matched?

• Abscisic acid -  Stomatal closure

• Gibberellic acid - Leaf fall

• Cytokinin - Cell division

• Cytokinin - Cell division

Pineapple (ananas) fruit develops from

• a unilocular polycarpellary flower 

• a multipistillate syncarpous flower

• a cluster of compactly borne flowers on a common axis

• a cluster of compactly borne flowers on a common axis

Fruit and leaf drop at early stages can be prevented by the application of

• Cytokinins

• Ethylene

• Auxins

• Auxins

The Golgi complex participates in

• Fatty acid breakdown

• Formation of secretory vesicles

• Activation of amino acid

• Respiration in bacteria