Effect of light and dark rhythm on plants is known as:
1.  Photonasty
2.  Phototropism
3.  Photoperiodism
4.  Photomorphogenesis

Which plant is LDP:
1.  Tobacco
2.  Glycine max
3.  Mirabilis jalapa
4.  Spinach

The proteinaceous pigment which controls the activities concerned with light:
1.  Phytochrome
2.  Chlorophyll
3.  Anthocyanin
4.  Carotenoids

Which pigment absorbs the red and far red light:

1. Cytochrome

2. Phytochrome

3. Carotenoids

4. Chlorophyll

Nicotiana sylvestris flowers only during long days and N. tabacum flowers only during short days. If raised in the laboratory under different photoperiods, they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason for considering N. sylvestris and N. tabacum to be separate species:

1. They cannot interbreed in nature

2. They are reproductively distinct

3. They are physiologically distinct

4. They are morphologically distinct

One set of a plant was grown at 12 hours day and 12 hours night period cycles and it flowered while in the other set, the night phase was interrupted by a flash of light and it did not produce a flower. Under which one of the following categories will you place this plant?

1. Darkness neutral

2. Day neutral

3. Short day

4. Long day