What is incorrect regarding the results of experiments conducted on coleoptiles of canary grass and oats by Charles Darwin and Francis Darwin on phototropism?
1. Both plants grow toward the light source.
2. The tips of coleoptiles were covered with a metal foil and the coleoptiles did not grow toward light.
3. When the metal foil was removed they still not grew toward the light.
4. The growing region of the coleoptiles rather than their tips was covered and the coleoptiles grew toward the light.

Plant growth regulators do not:
1. act by altering gene expression.
2. have multiple effects.
3. function independently of other hormones.
4. control cell division and cell differentiation

The newly discovered PGR brassinosteroids have effects qualitatively similar to:
1. Auxins
2. Gibberellins
3. Cytokinins
4. Ethylene

The plant hormones that are produced by wounded plants and play a key role in controlling plant defences against herbivores as well as responsible for enchanting fragrance of jasmine are:
1. Brassinosteroids
2. Strigolactones
3. Jasmonates
4. Auxins