Plant Biology - Hormone Review
Review for plant biology grad student comprehensive exam, hormones
Questions and Answers
- 1.
This hormone promotes cell division, growth of lateral buds, and leaf expansion. Used artificially to extend cut flower life.
- A.
Auxin
- B.
Gibberellins
- C.
Ethylene
- D.
ABA
- E.
Cytokinin
Correct Answer
E. CytokininExplanation
Cytokinin is a hormone that promotes cell division, lateral bud growth, and leaf expansion. It is also used artificially to extend the life of cut flowers.Rate this question:
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- 2.
This hormone is responsible for promoting seed and bud dormancy, suspension of root growth, stomatal closure. Inhibits effects of other hormones.
- A.
CK
- B.
ABA
- C.
Auxin
- D.
Ethylene
- E.
GA
Correct Answer
B. ABAExplanation
ABA, or abscisic acid, is the hormone responsible for promoting seed and bud dormancy, suspension of root growth, and stomatal closure. It also inhibits the effects of other hormones. ABA plays a crucial role in regulating plant responses to environmental stresses such as drought and salinity. It helps plants conserve water by closing stomata, reducing transpiration, and promoting dormancy to survive unfavorable conditions. Additionally, ABA interacts with other hormones to maintain hormonal balance in plants.Rate this question:
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- 3.
This hormone is responsible for breaking dormancy in buds and seeds, inducing flowering, stem elongation.
- A.
CK
- B.
ABA
- C.
GA
- D.
Auxin
- E.
Ethylene
Correct Answer
C. GAExplanation
GA (gibberellic acid) is the hormone responsible for breaking dormancy in buds and seeds, inducing flowering, and promoting stem elongation. It plays a crucial role in plant growth and development by stimulating cell division and elongation. GA also regulates various physiological processes such as seed germination, leaf expansion, and fruit development. Overall, GA promotes plant growth by influencing the production of enzymes and proteins involved in these processes.Rate this question:
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- 4.
This hormone is responsible for shoot elongation, apical dominance, LR branching in roots, and RH initiation.
- A.
ABA
- B.
GA
- C.
Ethylene
- D.
Auxin
- E.
CK
Correct Answer
D. AuxinExplanation
Auxin is the hormone responsible for shoot elongation, apical dominance, lateral root branching in roots, and root hair initiation. It promotes cell elongation in shoots, inhibits the growth of lateral buds to maintain apical dominance, stimulates the formation of lateral roots, and induces the initiation of root hairs. Therefore, auxin is the correct answer for this question.Rate this question:
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- 5.
This hormone is responsible for ripening, leaf and flower senescence, abscission, RH development, promotes chloroplast development, regulates expression of ripening genes.
- A.
CK
- B.
ABA
- C.
Auxin
- D.
Ethylene
- E.
GA
Correct Answer
D. EthyleneExplanation
Ethylene is the correct answer because it is a hormone that is responsible for ripening fruits, leaf and flower senescence (aging and death), abscission (shedding of leaves and fruits), and the development of root hairs. It also promotes the development of chloroplasts, which are responsible for photosynthesis in plants. Ethylene also regulates the expression of ripening genes, further supporting its role in fruit ripening.Rate this question:
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- 6.
What hormone slows leaf aging?
- A.
ABA
- B.
GA
- C.
CK
- D.
Auxin
- E.
Ethylene
Correct Answer
C. CKExplanation
CK (Cytokinin) is a hormone that slows down leaf aging. It promotes cell division and delays the process of leaf senescence. This hormone helps in maintaining the greenness and vitality of leaves by preventing the breakdown of chlorophyll and other essential components.Rate this question:
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- 7.
What is the pH of the cell wall and cytoplasm?
- A.
6 and 4
- B.
7 and 5
- C.
5 and 7
Correct Answer
C. 5 and 7Explanation
The pH of the cell wall is 5 and the pH of the cytoplasm is 7. The cell wall is slightly acidic, while the cytoplasm is slightly basic. This difference in pH is important for maintaining the proper functioning of the cell. The acidic environment of the cell wall helps to protect the cell from external threats, while the slightly basic cytoplasm is necessary for various cellular processes to occur.Rate this question:
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- 8.
Auxin is an anion at what pH? Neutral at what pH?
- A.
Anion at pH 7, neutral at pH 5
- B.
Anion at pH 5, neutral at pH 7
Correct Answer
A. Anion at pH 7, neutral at pH 5Explanation
Auxin is a plant hormone that functions as an anion at pH 7, meaning it carries a negative charge at this pH level. However, at pH 5, auxin is neutral, meaning it does not carry any charge. This change in charge is likely due to the ionization of auxin molecules in different pH environments.Rate this question:
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Current Version
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Mar 20, 2023Quiz Edited by
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Jul 27, 2009Quiz Created by
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