Importance of day length in flowering of plants was first shown in 

1. Lemna

2. tobacco

3. cotton

4. Petunia

Opening of floral buds into flowers, is a type of:-

1. autonomic movement of locomotion

2. autonomic movement of variation

3. paratonic movement of growth

4. autonomic movement of growth

“Foolish seedling" disease of rice led to the discovery of:-

1. GA

2. ABA

3. 2,4-D

4. IAA

Which one of the following pairs, is not correctly matched?

1. Abscisic acid - Stomatal closure

2. Gibberellic acid - Leaf fall

3. Cytokinin - Cell division 

4. IAA - Cell wall elongation

How does pruning help in making the hedge dense:-

1. It induces the differentiation of new shoots from the rootstock

2. It frees axillary buds from apical dominance

3. The apical Shoot grows faster after pruning

4. It releases wound hormones

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

1. α-amylase   

2. lipase

3. protease     

4. invertase

Vernalization is the process of

1. flower induction by high temperature treatment

2. inhabitation of flowering by low temperature treatment

3. flower induction by light treatment

4. acceleration of the ability of a plant to produce flowers by chilling treatment

Parthenocarpy in grapes is induced by:-

1. cytokinins

2. gibberellins

3. topoisomerases

4. primase

Phytochromes play a role in 

(1) seed germination

(2) flowering 

(3) photomorphogenesis

(4) photosynthesis.

Induction of flowering by low temperature in plants is 

1. cryobiology

2. vernalization 

3. phototropism

4. pruning.