The biologically active form of the phytochrome is:
1.${\mathrm{P}}_{\mathrm{r}}$
2. ${\mathrm{P}}_{\mathrm{fr}}$
3. Both
4. None

When lettuce seeds illuminated by red light are then exposed to far red light:

1. ${\mathrm{P}}_{\mathrm{r}}$ is converted to ${\mathrm{P}}_{\mathrm{fr}}$ and germination is inhibited
2. ${\mathrm{P}}_{\mathrm{r}}$ is converted to ${\mathrm{P}}_{\mathrm{fr}}$ and germination is initiated
3. ${\mathrm{P}}_{\mathrm{fr}}$ is converted to ${\mathrm{P}}_{\mathrm{r}}$ and germination is inhibited
4. ${\mathrm{P}}_{\mathrm{fr}}$ is converted to ${\mathrm{P}}_{\mathrm{r}}$ and germination is initiated

Etiolated seedlings become normal when exposed to:
1. Blue light
2. Green light
3. Red light
4. Far red light

An incandescent light bulb has a high output of red light. Which of the following plant process will be least promoted by it:
1. photosynthesis.
2. seed germination.
3. phototropism.
4. flowering.

The most important colors in regulating photomorhogenesis in plants are:
1. Violet and Yellow
2. White and Black
3. Green and Orange
4. Red and Blue

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

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

Hyponastic response in submerged plants may be due to auxin and:
1. ABA
2. Ethylene
3. Cytikinin
4. Gibberellins

Many mutants that are especially prone to wilting are deficient in:
1. ABA
2. Ethylene
3. Cytokinins
4. Gibberellins

The control of apical dominance is due to interaction of auxins, cytokinins and a newly discovered plant hormone called as:
1. Brassinosteroids
2. Jasmonates
3. Salicylic acid
4. Strigolactones