CBSE Class 11 Biology Plant Growth and Development MCQs Set D

Question: Which GA was the first Gibberellin to be discovered?
a) GA₄
b) GA₃
c) GA₁
d) GA₂
Answer: b

Question: Removal of shoot tips (decapitation) means loss of apical dominance and it is widely applied in
a) Bolting
b) Tea plantation
c) Both
d) Hedege-making
Answer: c

Question: The most widely used compound as a source of C₂H₄ is
a) Zeatin
b) Ethepon
c) IBA
d) Kinetin
Answer: b

Question: Zeatin is
a) an auxin
b) a cytokinin
c) a GA
d) None
Answer: b

Question: Which one(s) is acidic in nature?
a) ABA
b) All
c) GA
d) Auxin
Answer: b

Question: Long day plants flower specially when the?
a) Light period is lesser than some critical length
b) Dark period is more than some critical length
c) Light period is greater than some critical period
d) Dark period is less than some critical length
Answer: c

Question: Which of the following plant hormones can cause the base of a shoot to form new early stage, to be used as herbicide / weedicide, also controls xylem differentiation and helps in cell division?
a) Auxin
b) Cytokine
c) ABA
d) GA
Answer: a

Question: Which hormone promotes female flowers in cucumber?
a) ABA
b) C₂H₄
c) GA₃
d) GA₄
Answer: b

Question: Cytokinins are formed primarily in which area of the plant?
a) Root
b) Tips of shoot
c) Stem
d) Lateral buds and leaves
Answer: a

Question: Which is false?
a) GA₃ cannot increase the length of internode in sugarcane
b) GA₃ is commercially available gibberellin
c) Spraying juvenile conifers with GA3 hastens the maturity
d) GA₃ is used to speed up the malting process
Answer: a

Question: During ripening of the fruits, rate of respiration is increased under the influence of hormone. The hormone is
a) GA
b) C₂H₄
c) Auxin
d) ABA
Answer: b

Question: Removal of auxin source demonstrates that leaf abscission is _____ by auxin, and apical dominance is _____ by auxin
a) Inhibited, inhibited
b) Inhibited, promoted
c) Promoted, inhibited
d) Promoted, promoted
Answer: c

Question: Two cytokinins are kinetin and Zeatin. What is the difference between the two?
a) Zeatin is the active form of kinetin
b) Zeatin is naturally occurring plant cytokinin, kinetin is not
c) Kinetin is the active form of zeatin
d) Zeatin is synthetic cytokinin and kinetin is naturally occurring
Answer: b

Question: Which of the following diagram shows coleoptile bending toward light?
a) 3 and 4
b) 2 and 3
c) 1 and 2
d) 1 and 4
Answer: a

Question: Natural cytokinins are synthesised in
a) Root apices
b) Developing shoot buds
c) All
d) Young fruits
Answer: c

Question: Cytokinins help to produce all except
a) Rooting on stem cut
b) Chloroplast in leaves
c) New leaves
d) Lateral shoot growth and adventitious shoot formation
Answer: a

Question: C₂H₄ is synthesised in large amount by-
a) Root tip
b) Shoot tip
c) Young leaves
d) Tissues undergoing senescence and ripening fruits
Answer: d

Question: Spraying sugarcane with gibberellin increases the yield by as much as 20 tonnes per acre. GA makes this possible
a) By improving the quality of fruit
b) By internodal elongation
c) By making plants with rosette habit
d) None
Answer: b

Question: Seed dormancy is regulated by-
a) ABA
b) C₂H₄
c) IAA
d) GA₃
Answer: a

Question: Branching is inhibited by _____ from the tip of a growing shoot but this effect is countered by _____ from the root
a) GA, ABA
b) GA, Cytokine
c) Cytokine, auxin
d) Auxin, Cytokine
Answer: d

Question: The fruits can be left on the tree longer so as to extend the marked period. This is due to which function of GA?
a) Internodal elongation
b) Delay senescence
c) Bolting
d) Parthenocarpy
Answer: b