Callus from internodal segments of tobacco stem gets proliferated only if in addition to one of the following – extracts of vascular tissues, yeast extract, coconut milk or DNA, the nutrient medium also contains:

1.	Auxins	2.	Gibberellins
3.	ABA	4.	Ethylene

Auxin was first isolated from:

Auxin does not:
1. Help to initiate rooting in stem cuttings
2. Promote female flowers in cucumbers
3. Prevent fruit and leaf drop in early stages
4. Promote abscission of older mature leaves and fruits

To extend their market period, fruits can be left on trees longer by the application of:

Kinetin was first discovered from:

Cytokinins do not help in:
1. Production of new leaves                 
2. Lateral shoot growth
3. Adventitious shoot formation             
4. Promotion of apical dominance

Cytokinins help in delay of leaf senescence because they:

Normally, when the seeds are mature, ethylene production increases and builds-up within the fruit, resulting in a climactic event that means:

Which PGR is used to initiate flowering and for synchronizing fruit set in pineapple?

Which PGR stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stress?