Objective Questions

Question. Growth is accompanied by
(a) anabolic process and energy
(b) catabolic process which occurs at the expense of energy.
(c) metabolic processes which occur at the expense of energy
(d) energy only

Question. The method that renders the seed coat permeable to water so that embryo expansion is not physically retarded is called
(a) vernalization
(b) stratification
(c) denudation
(d) scarification

Question. The measure of the ability of the plant to produce new plant material is referred as —
(a) efficiency index
(b) absolute growth rate
(c) arithmetic growth
(d) linear growth

Question. The ability of plant to follow different pathways and produce different structures in response to environment and phases of life is termed as —
(a) elasticity
(b) growth efficiency
(c) plasticity
(d) heterophylly

Question. The hormones which was first isolated from human urine is.
(a) indole-3-acetic acid
(b) gibberellin
(c) ethylene
(d) kinetin

Question. Auxin herbicide is —
(a) NAA
(b) IAA
(c) 2, 4-D
(d) IBA

Question. Dwarfness can be controlled by treating the plant with —
(a) cytokinin
(b) gibberellic acid
(c) auxin
(d) antigibberellin

Question. Which one is the first Gibberellins to be discovered and remains the most intensively studied form?
(a) GA₁
(b) GA₂
(c) GA₃
(d) GA₀

Question. The most abundant natural cytokinin that is isolated from corn kernels and coconut milk is —
(a) carotenoid derivative
(b) pyrimidine derivative
(c) inetin
(d) zeatin

Question. Highest concentration of cytokinin is found in
(a) area of continuous growth and meristematic region.
(b) meristematic region only.
(c) mature leaves.
(d) ripened fruit.

Statement Type Questions

Question. Which of the following statement is not the characteristic of growth of an organism?
(a) It is an irreversible permanent increase in size of an organ / its part / an individual cell.
(b) It is accompanied by metabolic processes.
(c) It is quantitative and intrinsic.
(d) None of the above

Question. Which one of the following statement regarding auxin is 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, IAB, 2, 4-D and 2, 4, 5-T are synthetic auxins.

Question. Which of the following is an incorrect statement?
(a) Long day plants flower if the night length is shorter than a critical period.
(b) Short-day plants flower when night length exceeds a critical dark period.
(c) Day-neutral plants are insensitive to day length.
(d) The process of flowering does not occur in dayneutral plants.

Assertion/Reason Type Questions

In the following questions, a statement of Assertion is followed by a statement of Reason.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question. Assertion : 2, 4-D is extensively used in agricultural and horticultural practices.
Reason : 2, 4-D is a herbicide.

Question. Assertion : The most widely used compound as source of ethylene is ethephon.
Reason : Ethephon hastens fruit ripening in tomatoes and apples and accelerates abscission in stems and leaves.

Critical Thinking Type Questions

Question. Which hormone is used to induce rooting from cut end of the stem?
(a) Kinetin
(b) Indole butyric acid
(c) GA₃
(d) Abscisic acid

Question. Flowering in pineapple is promoted by
(a) GA₁
(b) C₂H₄
(c) NAA
(d) Kinetin

Question. Removal of apical (terminal) bud of a flowering plant (or pruning of a flowering plant) leads to
(a) formation of new apical buds.
(b) formation of adventitious roots on the cut side.
(c) early flowering (or stopping of floral growth).
(d) promotion of lateral branches.

Question. The chemicals from an unlabelled bottle of plant hormone when applied to a plant, a curvature induced by light is found in the stem. The chemical is most probably a
(a) auxin
(b) gibberellin
(c) kinetin
(d) ABA

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

Question. Which of the following hormone regulates the transition from juvenile to adult phases in confers?
(a) Cytokinins
(b) GA₀
(c) ABA
(d) IAA

Question. Farmers in a particular region were concerned that premature yellowing of leaves of a pulse crop might cause a decrease in the yield. Which treatment could be most beneficial to obtain maximum seed yield?
(a) Removal of all yellow leaves and spraying the remaining green leaves with 2, 4, 5-trichlorophenoxy acetic acid.
(b) Frequent irrigation of the crop.
(c) Treatment of the plants with cytokinins along with small doses of nitrogenous fertilizer.
(d) Application of iron and magnesium to promote synthesis of chlorophyll.

Question. Climacteric in the plants means
(a) increase in respiration rate before the ripening phase.
(b) decrease in respiration rate before the ripening phase.
(c) increase in respiration rate after the ripening phase.
(d) decrease in respiration rate after the ripening phase.

Question. Which one of the following phytohormones is produced under water deficient condition and plays an important role in the tolerance response of plants to drought?
(a) Abscisic acid
(b) Cytokinin
(c) Ethylene
(d) Gibberellin

Question. What type of plants will flower when short photoperiods are followed by long photoperiods?
(a) Long-short day plants
(b) Short-long day plants
(c) Intermediate plants
(d) None of these

Question. Which one of the following is not a mechanical method for breaking seed dormancy?
(a) Abrasions with knives
(b) Abrasions with sandpaper
(c) Vigorous shaking into the flask
(d) By the action of microbes

Question. Differentiation of shoot is controlled by
(a) high gibberellin : cytokinin ratio.
(b) high auxin : cytokinin ratio.
(c) high cytokinin : auxin ratio.
(d) high gibberellin : auxin ratio.