Plant Growth and Development Class 11 Biology Important Questions

Important Questions Class 11

Objective Questions

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

Answer

B

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

Answer

D

Question. Zeatin is
(a) An auxin
(b) a GA
(c) a cytokinin
(d) None

Answer

C

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

Answer

D

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

Answer

D

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

Answer

C

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

Answer

B

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

Answer

D

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

Answer

B

Question. Long day plants flower specially when the?
(a) Light period is lesser then some critical length
(b) Light period is grater then some critical period
(c) Dark period is less then some critical length
(d) Dark period is more then some critical length

Answer

B

Question. The following diagram shows four coleoptile set up at the start of an experiment

Plant Growth and Development Class 11 Biology Important Questions

Which two coleoptile will both bend towards the light source?
(a) 1 and 2
(b) 1 and 4
(c) 2 and 3
(d) 3 and 4

Answer

D

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

Answer

C

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

Answer

B

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) GA
(b) Cytokine
(c) Auxin
(d) ABA

Answer

C

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

Answer

C

Question. Which one(s) is acidic in nature?
(a) Ausin
(b) GA
(c) ABA
(d) All

Answer

D

Question. Which GA was the first Giberrellin to be discovered?
(a) GA1
(b) GA2
(c) GA3
(d) GA4

Answer

C

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) Bolting
(b) Delay senescence
(c) Internodal elongation
(d) Parthenocarpy

Answer

B

Question. Spraying surgarcane 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 making plants with rosette habit
(c) By internodal elongation
(d) None

Answer

C

Question. Which one is false?
(a) GA3 is used to speed up the malting process in brewing industry
(b) Spraying juvenile conifers with GA3 hastens the maturity, thus leading to early seed production
(c) GA3 is commercially available gibberellin
(d) GA3 cannot increase the length of internode in sugarcane

Answer

D

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

Answer

D