Plant Growth and Development Test - 5

This is the correct option as statement 'a' is false. Zeatin was the first natural cytokinin that was obtained from unripe maize grains and coconut milk. Kinetin does not occur naturally.

Ethylene aids in ripening of climacteric fruits and dehiscence of dry fruits.

Application of minute quantity of abscisic acid to leaves reduces transpiration to a great extent through partial closure of stomata. It conserves water and reduces the requirement of irrigation.

Campanula medium is a short-long day plant. Short-long day plants require short photoperiods for floral initiation and long photoperiods for blossoming and usually come to flower between spring and summer.

 ( Scarification, Stratification and Counteracting inhibitors) are the methods of artificially breaking the seed dormancy.

Severing branches during the pruning process interrupts or disconnects the chemical pathways that influence root and shoot growth, the auxin-cytokinin pathway. Basically, the cytokinins follow the established route until the top of the branch is removed through pruning. Due to the missing shoot which produces auxin, the latent buds on the truncated branches break dormancy; develop new stems; and produce new, weakly attached shoots. The concentration of cytokinins increases, flushing new growth below the location of the cut.

Morphactins are a group of substances which act on morphogenesis and modulate the expression of plants. Thus, they act as growth regulators in plants. Chemically, they are the derivates of fluorene compounds.

The short day plant is Impatiens.

The origin of parts or organs and the gross form of the plant is called morphogenesis. The pattern of growth is sigmoid in plants or plant parts.

Gibberellic acid was first isolated from Giberella fujikuroii. Gibberellic acid is a simple gibberellin, a pentacyclic diterpene acid promoting growth and elongation of cells. It affects decomposition of plants and helps plants grow if used in small amounts, but eventually plants develop tolerance to it.