The phytohormone which is supposed to be one of the factor responsible for regulating the opening and closing of stomata:

1. ABA

2. GA

3. IBA

4. Kinetin

When a plant is flooded it often increases its production of

1. cytokines

2. ethylene

3. gibberellins

4. all of the above

The plant hormone, _______________ , plays a role in closing of stomata.

1. auxin

2. Cytokinin

3. gibberellin

4. ABA

What is the site of perception of photoperiod necessary for induction of flowering in plants?

1. Leaves

2. Lateral buds

3. Pulvinus

4. Shoot apex

It takes a very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield?

1. Cytokinin and Abscisic acid

2. Auxin and Ethylene

3. Gibberellin and Cytokinin

4. Gibberellin and Abscisic acid

An enzyme that can stimulate the germination of barley seeds is:

1. $\mathrm{\alpha }$-amylase

2. lipase

3. protease

4. invertase

Parthenocarpic tomato fruits can be produced by:

The typical growth curve in plants is:

The Avena curvature is used for bioassay of?

Phytochrome is a:

1. flavoprotein

2. glycoprotein

3. lipoprotein

4. chromoprotein