Engineering Questions with Answers - Multiple Choice Questions

MCQs on Plant Hormones

1 - Question

Growth regulators, which control plant growth and development are called___________
a) Secondary metabolites
b) Macro element
c) Nonessential elements
d) Phytohormone

View Answer

Answer: d
Explanation: Phytohormones or plant hormones are the small organic compound which is synthesized by specific cells/tissues in low concentration and promote the growth and development of the plant.

2 - Question

Growth in plants is mainly driven by turgor pressure.
a) True
b) False

View Answer

Answer: a
Explanation: During the growth, cells in plant increase in the volume and become highly vacuolated, this is basically due to the turgor pressure. Plant growth is defined as an irreversible increase in size or volume.

3 - Question

Which of the following is NOT a plant hormone?
a) Corticosteroid
b) Brassinosteroid
c) Polyamines
d) Salicylic acid

View Answer

Answer: a
Explanation: Corticosteroid is an animal hormone, which is produced in the adrenal cortex of the vertebrates while brassinosteroid, polyamines and salicylic acid are plant hormones.

4 - Question

Name the plant in which auxin was first discovered?
a) Mustard
b) Pea
c) Oats
d) Rice

View Answer

Answer: c
Explanation: Auxin is a first plant hormone which was discovered by Frits Went in the tip of the oats (Avena sativa) coleoptiles.

5 - Question

Which of the following is NOT a naturally occurring auxin?
a) Indole 3-acetic acid (IAA)
b) Indole 3-butyric acid (IBA)
c) Phenyl acetic acid (PAA)
d) 2,4-D

View Answer

Answer: d
Explanation: 2, 4-D is an organic compound and is known as synthetic auxin which is marketed as a herbicide.

6 - Question

Name the amino acid which acts as a precursor of auxin biosynthesis?
a) Serine
b) Tryptophan
c) Valline
d) Tyrosine

View Answer

Answer: b
Explanation: The basic chemical structure similarity between indole 3-acetic acid and tryptophan proves the connection between them. The conversion of tryptophan to auxin takes place by tryptophan dependent pathway.

7 - Question

Mark the one, which is NOT a physiological effect of auxin?
a) Cell elongation
b) Stem elongation
c) Cell differentiation
d) Rooting

View Answer

Answer: b
Explanation: Stem elongation is the physiological effect of Gibberellins not Auxin. Auxin involves in cell elongation, rooting, and cell differentiation.

8 - Question

Name the site of Gibberellins synthesis
a) Endosperm
b) Coleoptile tip
c) Young leaves
d) Scetullum

View Answer

Answer: a
Explanation: Biosynthesis of Gibberellins takes place in the apical tissues and young leaves of the plant. Sometimes root tissues also produce Gibberellins.

9 - Question

Gibberellin that is synthesized in the shoot transported to different parts of the plant by which medium?
a) Xylem
b) Sieve tube
c) Aleurone layer
d) Phloem

View Answer

Answer: d
Explanation: After synthesis Gibberellins transported to rest of the plant by phloem but the Gibbrellins which synthesized in roots are transported to shoots by the xylem.

10 - Question

What is bolting?
a) Internode elongation
b) Rooting
c) Shooting
d) Shoot apical meristem

View Answer

Answer: a
Explanation: Bolting has defined as a phenomenon of Internode elongation just before the flowering of the plant. It is normally triggered by environmental signals.

11 - Question

Which of the following plant hormone is responsible for seed germination?
a) Auxin
b) Gibberellin
c) Ethylene
d) Abscisic acid

View Answer

Answer: b
Explanation: Gibberellin activates vegetative growth of the embryo by promoting the utilization of reserve food which is stored in the endosperm.

12 - Question

Name the first naturally occurring cytokines.
a) Neoxanthin
b) Xanthoxin
c) Zeatin
d) Isopentenyl adenine

View Answer

Answer: c
Explanation: Zeatin was the first naturally occurring cytokines, which was isolated by Miller and Letham in 1955 from the corn.

13 - Question

Which of the following plant hormone causes a delay in leaf senescence?
a) Abscisic acid
b) Ethylene
c) Auxin
d) Cytokines

View Answer

Answer: d
Explanation: Senescence is an aging process which is an energy driven genetic program. Presence of cytokines delay in leaf senescence.

14 - Question

Name the stress hormone of the plant.
a) Brassinosteroid
b) Abscisic acid
c) Cytokines
d) Ethylene

View Answer

Answer: b
Explanation: Abscisic acid is a plant stress hormone which was first identified as a compound responsible for abscission of cotton fruits.

15 - Question

Deficiency in which of the following hormone causes dwarfism in the plant?
a) Ethylene
b) Abscisic acid
c) Gibberellin
d) Brassinosteroid

View Answer

Answer: d
Explanation: Brassinosteroid is chemically similar to the animal hormone and are responsible for the promotion of cell division, cell elongation and differentiation.

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