HORTICULTURE

Detailed explanation-1: -Auxins are a group of naturally occurring and artificially synthesised plant hormones. They play an important role in the regulation of plant growth. Auxins were initially isolated from human urine. Auxin means to “enlarge” or “increase”.

Detailed explanation-2: -Answer: Auxin promotes cell growth and elongation of the plant. In the elongation process, auxin alters the plant wall plasticity making it easier for the plant to grow upwards. Auxin also influences rooting formations.

Detailed explanation-3: -Auxin promotes cell division and meristem maintenance and also plays an important role in the establishment of cellular patterning. Plant development thus integrates the regulation of cell proliferation and growth with further cell expansion and differentiation.

Detailed explanation-4: -Auxin and cytokinin are critical growth hormones in plant development and are naturally present within the plant at variable concentrations throughout the season. Their presence and activity are different from other hormones which act more in an on-off manner and are present only at specific times.

Detailed explanation-5: -(i) In light, hormone auxin, helps the cells to grow longer in plants. (ii) Plant hormone gibberellins help in growth of a stem.