This set of Plant Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Photoperiodism and Flowering”.
1. Who first introduced the concept of photoperiodism?
a) Carlos Miller
b) Agnes Arber
c) W. W. Garner and H. A. Allard
d) Toshio Murashige and Folke Karl Skoog
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Explanation: The concept of photoperiodism was first introduced by W. W. Garner and H. A. Allard in the year of 1920. They conducted several experiments to test the effect of day length on flowering and concluded that the length of daylight is the main factor for flowering.
2. Critical day length is defined as the photoperiod required to induce/inhibit flowering in plants.
a) True
b) False
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Explanation: The given statement is true. Critical day length can be defined as the photoperiod required to induce flowering in long day plants or to inhibit flowering in short day plants. It generally denotes the length of light period in a 24-hour cycle.
3. Which of the following is an example of LDP?
a) Cannabis sativa
b) Pisum sativum
c) Glycine max
d) Nicotiana tabacum
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Explanation: Long-day plants (LDP) are those that require a photoperiod, typically, more than the critical threshold to produce flowers. Examples of long-day plants include: Pisum sativum, Beta vulgaris, Triticum aestivaticum, Spinacea etc.
4. Which of the following is an example of SDP?
a) Brassica
b) Raphanus sativus
c) Helianthus annuus
d) Hyoscyamus niger
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Explanation: The plants that can flower when the day length is less are known as short-day plants. These plants usually require long period of darkness for flowering. Examples of short-day plants include: Helianthus annuus, Gossypium, Cucumis sativus etc.
5. Soyabean is an example of which plant type?
a) Long-day plant
b) Short-day plant
c) Day-neutral plant
d) Daylight plant
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Explanation: Soyabean is an example of short-day plant. Day-neutral plant are those that flowers irrespective of the length of the period of light. Rose, corn and tomatoes are common examples of DNPs.
6. Which of the following is true about phytochrome?
a) It is a photosynthetic pigment
b) The site of phytochrome production is stem
c) It is a biological proteinaceous pigment
d) Phytochromes produce fluorescence
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Explanation: Phytochromes are biological proteinaceous pigment which are non-photosynthetic. The major site of phytochrome is leaves, especially those that are matured. In general, Phytochromes can be classified into two based on light absorption.
7. Which hormone promotes flowering in long day plants?
a) Gibberellin
b) Cytokinin
c) Ethylene
d) Abscisic acid
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Explanation: Gibberellin hormone promotes flowering in long day plants. Similarly, they regulate other growth and developmental processes in other plant varieties. It has been observed that gibberellins are also involved in bolting process.
8. Florigen is a type of hormone that induces flowering.
a) True
b) False
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Explanation: Florigen also known as flowering hormone, plays a major role in inducing the flowering mechanism. This hormone is produced in the leaves and thus acts on the apical meristem region especially in buds and growing tips.
9. What do you mean by nycto period?
a) Photoperiod in day-neutral plants
b) Photoperiod in nitrogenous plants
c) Length of day
d) Length of night
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Explanation: Nycto period or dark period means ‘length of night’. It has a significant role in photoperiodism reactions as well as in plant growth development. They tend to influence the flowering process in both LDP and SDP.
10. What type of photoperiodism is found in passion fruit?
a) Long day
b) Short day
c) Day neutral
d) Long night
View Answer
Explanation: Passion fruit is classified as a long day plant. Primarily, Photoperiodism can be categorized into three groups according to the photoperiod. They are short-day plants, long-day plants, and day-neutral plants.
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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