1. What is photoperiodism in plants?
A) Response to temperature
B) Response to light duration
C) Response to water availability
D) Response to humidity
Answer: B) Response to light duration
2. The phenomenon of flowering in plants influenced by the length of day and night is called:
A) Vernalization
B) Photoperiodism
C) Germination
D) Dormancy
Answer: B) Photoperiodism
3. Which of the following is a short-day plant?
A) Wheat
B) Poinsettia
C) Tomato
D) Sunflower
Answer: B) Poinsettia
4. Long-day plants typically flower when:
A) Day length is shorter than the critical period
B) Day length is equal to the night length
C) Day length exceeds a critical length
D) Day length is very short
Answer: C) Day length exceeds a critical length
5. Which plant is an example of a long-day plant?
A) Rice
B) Cotton
C) Spinach
D) Chrysanthemum
Answer: C) Spinach
6. Photoperiodic response in plants is controlled by which pigment?
A) Chlorophyll
B) Phytochrome
C) Carotenoid
D) Xanthophyll
Answer: B) Phytochrome
7. The light-sensitive pigment in photoperiodism is located in:
A) Chloroplasts
B) Nucleus
C) Cytoplasm
D) Leaf cells
Answer: D) Leaf cells
8. Which of the following is the main environmental factor responsible for photoperiodism?
A) Temperature
B) Water availability
C) Light duration
D) Soil pH
Answer: C) Light duration
9. What is the role of phytochrome in photoperiodism?
A) It absorbs water from the soil
B) It helps in the conversion of light energy into chemical energy
C) It helps plants detect the length of day and night
D) It causes cell division in roots
Answer: C) It helps plants detect the length of day and night
10. What is vernalization in plants?
A) The process of growing in warm temperatures
B) The process of cold treatment to induce flowering
C) The process of photosynthesis
D) The process of water absorption
Answer: B) The process of cold treatment to induce flowering
11. Which of the following is a plant that requires vernalization to flower?
A) Cabbage
B) Maize
C) Wheat
D) Sunflower
Answer: C) Wheat
12. Vernalization is most effective when:
A) The plant is exposed to high temperatures
B) The plant is exposed to light
C) The plant is exposed to low temperatures for a period
D) The plant is watered frequently
Answer: C) The plant is exposed to low temperatures for a period
13. Which of the following can cause premature flowering in plants?
A) Exposure to prolonged darkness
B) Exposure to long-day conditions
C) Exposure to excessive heat
D) Exposure to cold temperatures
Answer: B) Exposure to long-day conditions
14. Which term refers to plants that flower when exposed to long days?
A) Short-day plants
B) Long-day plants
C) Day-neutral plants
D) Night-neutral plants
Answer: B) Long-day plants
15. The critical photoperiod is the duration of light:
A) Required for seed germination
B) That controls plant flowering
C) Needed for photosynthesis
D) That induces dormancy
Answer: B) That controls plant flowering
16. Short-day plants flower when:
A) The day length is longer than a critical period
B) The night length is longer than a critical period
C) Day and night length are equal
D) The temperature is high
Answer: B) The night length is longer than a critical period
17. Phytochrome exists in which two forms?
A) Active and inactive
B) Neutral and charged
C) Transient and stable
D) Light and dark
Answer: A) Active and inactive
18. Which of the following does not exhibit photoperiodism?
A) Pea
B) Spinach
C) Corn
D) Sunflower
Answer: C) Corn
19. Vernalization helps in the flowering of:
A) Plants growing in tropical regions
B) Plants grown in extreme cold
C) Annual plants that require cold
D) Plants in arid climates
Answer: C) Annual plants that require cold
20. What happens if a long-day plant is kept in short-day conditions?
A) It will flower
B) It will not flower
C) It will produce fruits
D) It will grow faster
Answer: B) It will not flower
21. In photoperiodism, which of the following is most important for a plant to detect day length?
A) Leaf color
B) The presence of chlorophyll
C) The concentration of phytochrome
D) Root system
Answer: C) The concentration of phytochrome
22. Which of the following plants is an example of a day-neutral plant?
A) Strawberry
B) Spinach
C) Wheat
D) Rice
Answer: A) Strawberry
23. Vernalization mainly affects which process in plants?
A) Photosynthesis
B) Seed germination
C) Flowering
D) Root development
Answer: C) Flowering
24. Which of the following is true about photoperiodism?
A) It only influences seed production
B) It is unaffected by temperature
C) It affects flowering and fruiting in plants
D) It only affects vegetative growth
Answer: C) It affects flowering and fruiting in plants
25. The phytochrome system can sense:
A) The temperature of the environment
B) The length of the day
C) The humidity of the soil
D) The rate of photosynthesis
Answer: B) The length of the day
26. Short-day plants are sensitive to:
A) Longer days
B) Shorter nights
C) Longer nights
D) Longer periods of light and dark
Answer: C) Longer nights
27. Which of the following is an example of a plant that requires vernalization?
A) Rice
B) Soybean
C) Lettuce
D) Carrot
Answer: D) Carrot
28. Photoperiodism is important for:
A) Controlling plant growth
B) Determining the time of flowering
C) Regulating root elongation
D) Affecting seed germination
Answer: B) Determining the time of flowering
29. Which of the following is the effect of vernalization on wheat?
A) It prevents flowering
B) It induces flowering
C) It inhibits seed germination
D) It increases vegetative growth
Answer: B) It induces flowering
30. Which of the following plants will flower in the presence of a short day?
A) Cotton
B) Wheat
C) Soybean
D) Chrysanthemum
Answer: D) Chrysanthemum
