131. Leaves of many grasses are capable of folding and unfolding because they

A are very thin
B are isobilateral
C have specialised bulliform cells
D have parallel vascular bundles
Answer :   have specialised bulliform cells
Discuss Question

132. The response of different organisms to environmental rhythms of light and darkness is called

A phototaxis
B photoperiodism
C phototropism
D vernalization
Answer :   photoperiodism
Discuss Question

133. Bolting hormone is

A Auxin
B Gibberellin
C ABA
D Enthylene
Answer :   Gibberellin
Discuss Question

134. In short day plants, flowering is induced by

A photoperiod less than 12 hours
B photoperiod below a critical length and uninterrupted long night
C long night
D short photoperiod and interrupted long night
Answer :   photoperiod below a critical length and uninterrupted long night
Discuss Question

135. Sensecence as an ative development cellular process in the growth and functioning of a flowering plant, is indicates in

A Annulal plants
B Floral parts
C Vessesl and tracheid differentiation
D Leaf abscission
Answer :   Leaf abscission
Discuss Question

136. Laeral axillary buds are not allowed to grow by

A Auxin
B Ethylene
C Gibberellin
D Cytokinin
Answer :   Auxin
Discuss Question

137. The pineapple which under natural conditions is difficult to blossom has been made to produce fruits throughout the year by application of

A IAA, IBA
B NAA, 2, 4-D
C Phenyl acetic acid
D Cytokinin
Answer :   NAA, 2, 4-D
Discuss Question

138. Gibberelling was first extracted from

A Fusarium moniliforme = Gibberella funjikuroi
B Gellidium
C Gracillaria
D Aspergillus
Answer :   Fusarium moniliforme = Gibberella funjikuroi
Discuss Question

139. Which one of the following generally acts as an antagonist to gibberellins?

A Zeatin
B Ethylene
C ABA
D IAA
Answer :   ABA
Discuss Question

140. Agent orange is

A Biodegradable insecticide
B Dioxin weedicide
C Biofertilizer
D Biopesticide
Answer :   Dioxin weedicide
Discuss Question


Practice More MCQ Question on Biology Section