The plant hormone used to destroy weeds in a field is:
1. 2, 4-D
2. IBA
3. IAA
4. NAA

Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called:
1. Plasticity
2. Maturity
3. Elasticity
4. Flexibility

The site of perception of light in plants during photoperiodism is:

1. Axillary bud

2. Leaf

3. Shoot apex

4. Stem

Which of the following is  not an inhibitory substance governing seed dormancy?

1. Abscisic acid

2. Phenolic acid

3. Para-ascorbic acid

4. Gibberellic acid

Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop.

1. Gibberellin

2. Ethylene

3. Abscisic acid

4. Cytokinin

Who coined the term 'Kinetin'?

1. Skoog and Miller

2. Darwin

3. Went

4. Kurosawa

Inhibitory substances in dormant seeds cannot be removed by subjecting seeds to:
1. Gibberellic acid
2. Nitrate
3. Ascorbic acid
4. Chilling conditions

Match the following concerning the activity/function and the phytohormone involved :-

(a) Fruit ripener         (i) Abscisic acid

(b) Herbicide             (ii) GA 3

(c) Bolting agent       (iii) 2, 4-D

(d) Stress hormone   (iv) Ethephon

Select the correct option from following :-

1. (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)

2. (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)

3. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

4. (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)

It takes 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

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