This set of Plant Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Phytohormones”.
1. Which plant hormone was the first to be discovered?
a) Cytokinin
b) Salicylic acid
c) Auxin
d) Gibberellin
View Answer
Explanation: Auxins are the first hormones that were discovered in plants. The term ‘Auxin’ is derived from Greek which denotes ‘To grow’. Auxins are known for their biological functions in plant growth regulation and development.
2. Brassinosteroids are a type of phytohormone.
a) True
b) False
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Explanation: The given statement is true. Brassinosteroids are one among the phytohormone that are involved in regulating the plant oxidation metabolism, ethylene synthesis and root gravitropic response, and they also mediate the plant’s response to stress.
3. Which of the following is a class of plant hormone?
a) Ascorbic acid
b) Ethylene
c) Adrenaline
d) Epinephrine
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Explanation: Plant hormones (Phytohormones) include auxins, gibberellins, cytokinin, salicylic acid, ethylene etc. Adrenaline and epinephrine are hormones that are present in animals, whereas ascorbic acid is another term for Vitamin C, which is not a class of phytohormone.
4. Which hormone is responsible for cell division in plants?
a) Auxin
b) Gibberellin
c) Ethylene
d) Cytokinin
View Answer
Explanation: The hormone responsible for cell division in plants is cytokinin. This hormone causes the plant cells to divide and influence its growth. Plants possessing increased amount of cytokinin shows slow science of aging.
5. The Abscission process is mediated only through abscisic acid.
a) True
b) False
View Answer
Explanation: The given statement is incorrect. Abscission is the process of detachment of parts (leaves, flowers, fruits, etc.) from the plant. This process is mediated not only by abscisic acid but also through ethylene. The ethylene hormone accelerates the rate of abscission to a larger extent.
6. Which of the following is a synthetic auxin?
a) Indole-3-acetic acid
b) 4-chloroindole-3-acetic acid
c) 2,4-dichlorophenoxy acetic acid
d) Phenylacetic acid
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Explanation: Synthetic auxin includes 1-naphthalene acetic acid, 2,4-dichlorophenoxy acetic acid and indole-3-butyric acid. The natural type of auxins includes indole-3-acetic acid, 4-chloroindole-3-acetic acid, phenylacetic acid and indole-3-propionic acid.
7. Which of the following is true regarding apical dominance?
a) Removal of apical buds promote lateral bud growth
b) Auxin stimulates lateral bud formation
c) Root and shoot in the apex are dormant
d) Decrease in cytokinin increases apical dominance
View Answer
Explanation: The auxin hormone produced in the apex region inhibits lateral bud growth in plants. Hence, removal of apical buds promotes lateral bud growth. And, in order to prevent apical dominance, the level of cytokinin is increased with respect to auxin.
8. Which hormone is also termed as dormin?
a) Auxin
b) Cytokinin
c) Abscisic acid
d) Ethylene
View Answer
Explanation: The term dormin is another representation for the hormone, abscisic acid because it induces dormancy in buds as well as in underground parts of the plant. These hormones are also known as stress hormones.
9. Who discovered gibberellin phytohormone?
a) Folke Karl Skoog
b) Toshio Murashige
c) Akira Kurosawa
d) Eiichi Kurosawa
View Answer
Explanation: Eiichi Kurosawa, a Japanese botanist, first discovered gibberellin produced by the fungus Gibberella fujikuroi. Gibberellin is considered to be the most important plant hormone because of its role in germination and plant growth.
10. Which hormone is responsible for seed dormancy?
a) Abscisic acid
b) Ethylene
c) Gibberellin
d) Cytokinin
View Answer
Explanation: The phytohormone responsible for seed dormancy in plants is abscisic acid. These hormones also control the closing of stomata. Ethylene promotes ripening of fruits and cytokinin is involved in the process of cell division.
11. Which part of plant synthesize cytokinin?
a) Leaf
b) Stem
c) Root
d) Flower
View Answer
Explanation: Cytokinin is usually synthesized in the roots. They are a derivation of adenine. The synthesized cytokinin is then transported from the roots to the leaves with the help of xylem, for cell differentiation and development purpose.
Sanfoundry Global Education & Learning Series – Plant Biotechnology.
To practice all areas of Plant Biotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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