31 Years NEET Previous Year Questions: Plant Growth & Development - 2 - NEET MCQ

Ethylene breaks dormancy of different plants. Abscisic acid induces dormancy in seeds, buds and underground storage organs

NAA or Naphthalene Acetic Acid is synthetic auxin. It is used to check fruit fall specially in tomato.

ABA or Abscisic acid is responsible for leaf fall or senescence.

Ethylene breaks seed and bud dormancy, initiates germination in peanut seeds, sprouting of potato tubers.

The medium in tissue culture provides all the essential nutrients required for growth and division of callus. Coconut milk contains cytokinins which is useful in tissue culture.

Gibberellins are involved in shoot elongation. Auxins are important in root elongation and cell division

Ethylene is a gaseous plant hormone which plays an important role in fruit ripening. In the presence of ethylene there is an increase in the rate of respiration.

 Apical buds inhibit lateral branching due to apical dominance. Removal of apical bud promotes lateral branching.

Cytokinin help in retaining chlorophyll, hence delay senescense.

Abscisic Acid (ABA) is called stress hormone which works in adverse environmental condition when there is low water content in atmosphere or in drought conditions. ABA causes the stomatal closure of leaves due to which the water loss by the plant is minimized.