CBSE Class 11 Biology Plant Growth and Development MCQs

Question : Which one is a long day plant?
a) Spinach
b) Mirabilis jalapa
c) Tobacco
d) Glycine max
Answer : A

Question : The hormone which controls cell division and cell differentiation is
a) cytokinin
b) auxin
c) ABA
d) gibberellin
Answer : A

Question : Which one of the following is a long day plant?
a) Wheat
b) Soyabean
c) Bajra
d) Tobacco
Answer : A

Question : A chemical believed to be involved in flowering is
a) florigen
b) gibberellin
c) kinetin
d) IBA
Answer : A

Question : Differentiation of shoot is controlled by
a) high cytokinin : auxin ratio
b) high gibberellin : auxin ratio
c) high auxin : cytokinin ratio
d) None of these
Answer : B

Question : Which one of the following generally acts as an antagonist to gibberellins?
a) ABA
b) Zeatin
c) Ethylene
d) IAA
Answer : A

Question : To avoid excessive water loss during severe drought stress,the closure of stomata is signalled by the production of
a) ABA
b) IAA
c) NAA
d) IBA
Answer : A

Question : In short day plants, flowering is induced by
a) photoperiod below a critical length and uninterrupted long night.
b) long night
c) short photoperiod and interrupted long night.
d) photoperiod less than 12 hours.
Answer : C

Question : Apical dominance in plants is caused by
a) high concentration of auxins in the terminal bud
b) high concentration of gibberellins in the apical bud
c) high concentration of auxins in the lateral bud
d) absence of auxins and gibberellins in apical bud
Answer : C

Question : Primary precursor of IAA is
a) tryptophan
b) phenylalanine
c) tyrosine
d) leucine
Answer : A

Question : Parthenocarpic fruit can be produced by the application of which of the following auxin?
a) All of the above
b) 2, 4-D (2-4 dichlorophenoxy acetic acid)
c) IAA (Indole acetic acid)
d) IBA (Indole butyric acid)
Answer : A

Question : The conditions necessary for vernalization are
a) water and carbon dioxide
b) oxygen and water.
c) low temperature and oxygen
d) high temperature and water
Answer : A

Question : Which of the following hormones does not naturally occur in plants?
a) 2,4–D (2, 4–dichloropheoxy acetic acid)
b) IAA
c) ABA
d) GA
Answer : A

Question : Which of the following types of phytohormones resemble the nucleic acids in some structural aspects ?
a) Cytokinin
b) ABA
c) Auxin
d) Gibberellin
Answer : B

Question : Which one of the following statement regarding auxin is/ are correct?
a) IAA and IBA are natural but NAA, 2, 4-D and 2, 4, 5-T are synthetic auxins
b) IAA and NAA are natural but IBA, 2, 4, 5-T and 2, 4-D are synthetic auxins
c) NAA and 2, 4, 5-T are natural but IAA, IBA and 2, 4-D are synthetic auxins
d) IAA, NAA, IBA, 2, 4-D and 2, 4, 5-T are synthetic auxins.
Answer : A

Question : Which one among the following chemicals is used for causing defoliation of forest trees?
a) 2, 4-dichlorophenoxy acetic acid
b) Malic hydrazide
c) Phosphon-D
d) None of these
Answer : A

Question : A plant completing its life cycle before the onset of dry condition is said to be
a) drought escaping
b) short day plant
c) long day plant
d) All of these
Answer : A

Question : Phytohormones are
a) regulators synthesized by plants and influencing physiological processes.
b) hormones regulating growth from seed to adulthood.
c) chemicals regulating secondary growth.
d) chemicals regulating flowering.
Answer : A

Question : Which one of the following is a natural growth inhibitor?
a) ABA
b) GA
c) NAA
d) IAA
Answer : B

Question : In a plant growing under dark condition, the leaves turn light coloured, internodes become much elongated and it is termed as
a) etiolation
b) chlorosis
c) vernalization
d) phyllotaxy
Answer : B