CBSE Class 11 Biology Plant Growth and Development MCQs Set 06

Question: Gaseous hormone is
a) benzaldehyde
b) ethane
c) ethylene
d) acetylene
Answer: c

Question: The historical experiment on canary grass coleoptile as a first step in the discovery of auxin was conducted by
a) Went
b) Darwin
c) Kogl
d) Kurosawa
Answer: b

Question: Which one includes growth promoters?
a) C₂H₄, ABA
b) GA, Cytokinin, C₂H₄
c) Auxin, Cytokinin, ABA
d) Auxin, Cytokinin, GA
Answer: d

Question: PGRs include
a) Only growth promoters
b) Only growth inhibitor
c) Only solid hormones, not gaseous hormones
d) Both growth promoters and growth inhibitor
Answer: d

Question: The hormone responsible for phototropism is
a) GA
b) ABA
c) Auxin
d) C₂H₄
Answer: c

Question: Which of the following synthetic phytohormone was discovered as a breakdown product of DNA?
a) 2,4-D
b) NAA
c) Kinetin
d) Thidiazuron
Answer: c

Question: 3-term inhibitor, abscission II and dormin are terms used for the same hormone. That hormone is
a) GA
b) ABA
c) Auxin
d) C₂H₄
Answer: b

Question: Plant growth substance generally
a) Have a single role
b) Are species-specific
c) Affects mainly the cells that produce them
d) Are produced in many parts of plant
Answer: d

Question: Which of the following hormone is concerned with climacteric respiration?
a) Cytokinin
b) GA₁
c) Auxin
d) Ethylene
Answer: d

Question: If a shoot cutting is treated with auxin, which of the following is likely to result?
a) Bolting of shoot
b) Growth of lateral buds
c) Extensive root production
d) Suppression of apical dominance
Answer: c

Question: Lead abscission, fruit fall and bud dormancy occur by which phytohormone?
a) Gibberellins
b) Auxin
c) Cytokinins
d) Abscisic acid
Answer: d

Question: ABA is antagonistic to
a) Auxin
b) Ethylene
c) Cytokinin
d) GA
Answer: d

Question: Photoperiodism is
a) growth curvature in response to light
b) flowering plant
c) effect of day length on flowering of a plant
d) recurrence of day and night
Answer: c

Question: Plants requiring exposure to light for less than critical period in order to flower are called
a) long day plants
b) intermediate day plants
c) short day plants
d) day neutral plants
Answer: c

Question: Effect of low temperature which shortens vegetative period and hastens flowering is called
a) transpiration
b) photoperiodism
c) photolysis
d) vernalization
Answer: d

Question: 6-furfuryl amino purine, 2,4-dichlorophenoxy acetic acid and indole-3-acetic acid are examples respectively of
a) natural auxin, kinetin and synthetic auxin
b) gibberellin, natural auxin and kinetin
c) synthetic auxin, kinetin and natural auxin
d) kinetin, synthetic auxin and natural auxin
Answer: d 

Statement Type Question

Question: Which of the following statement regarding vernalisation is correct?
a) Vernalisation refers to the promotion of flowering by a period of low temperature.
b) The spring variety of crops are normally planted in the spring and come to flower before the end of the growing season.
c) It is not seen in biennial plants.
d) Subjecting cold treatment to sugar beet will result in flowering.
Answer: c

Question: Which of the following statements on phytohormones & their action are correct?
(i) Cytokinins specially help in delaying senescence.
(ii) Auxins are involved in regulating apical dominance.
(iii) Ethylene is specially useful in enhancing seed germination.
(iv) Gibberellins are responsible for immature falling of leaves.
a) (i) and (iii) only
b) (i) and (iv) only
c) (i) and (ii) only
d) (ii) and (iii) only
Answer: c

Question: Refer the following statements.
(i) Promotes flowering in pineapple.
(ii) Used to prepare weed free lawn.
(iii) Promotes the abscission of older mature leaves and fruits.
The above functions are carried out by
a) GA
b) C₂H₄
c) ABA
d) Auxin
Answer: d 

Question: Refer the functions of the growth hormones given below.
I. Cell division
II. Cell enlargement
III. Pattern formation
IV. Tropic growth
V Flowering
VI. Fruiting
VII. Seed germination
VIII. Response to wound
IX. Response to stresses of biotic and abiotic origin
Identify the functions of growth promoters and growth inhibitors from the above.

Question: Which one of the following pairs is incorrectly matched?
(a) Adenine derivative – Kinetin
(b) Carotenoid derivative – ABA
(c) Terpenes – IAA
(d) Indole compounds – IBA
Answer: c

Critical Thinking Type Questions

Question: De-differentiation is
a) the ability of plant to produce different structures in response to environment.
b) none of the above.
c) regaining the lost capacity of division by living cells.
d) the intrinsic factor affecting plant growth.
Answer: c

Question: A phytohormone is
a) a pigment responds to environmental changes.
b) an ion that alters turgor pressure.
c) a secondary metabolic compound.
d) small molecules of diverse chemical composition.
Answer: d

Question: Ethylene is used for
a) slowing down ripening of apples.
b) ripening of fruits.
c) retarding ripening of tomatoes.
d) both (b) and (c).
Answer: b

Question: Maximal size in terms of wall thickening and protoplasmic modification are achieved by
a) cells of elongation phase.
b) cells of divisional phase.
c) cells of meristematic tissue.
d) cells of maturation phase.
Answer: d

Question: A sigmoidal curve is obtained in geometrical growth because
a) of the effect of environment on mitosis.
b) it has lag, log and then stationary phase.
c) one daughter cell remains meristematic while the other differentiates and matures.
d) none of the above
Answer: b

Question: The exponential growth can be expressed as W₁ = W₀ eʳᵗ. What is ‘r’ in the expression?
a) Absolute growth rate & depends on initial size.
b) Relative growth and also referred to as efficiency index.
c) Relative growth rate and depends on final size.
d) None of the above
Answer: b