Process of Flowering (Multiple Choice Questions and Answers)

Process of Flowering

Multiple Choice Questions and Answers

1. The compound responsible for red and far-red reversible photoperiodic reaction is

(a) cytokinin

(b) phytochrome

(c) cytochrome

(d) anthocyanin

Answer: (b) phytochrome

2. Which of the following is necessary for flower formation in higher plants?

(a) Water and minerals

(b) Florigen

(c) Phyllocaline

(d) None

Answer: (b) Florigen

3. If a brief flash of light is provided during dark period to the plant that requires a short day then the plant is likely

(a) to flower

(b) not to flower

(c) to have no effect

(d) produces more flowers

Answer: (b) not to flower

4. In many plants, change over from vegetative phase to reproductive phase takes place in response to

(a) the length of the day

(b) the severity of temperature

(c) mainly the food material available in the soil

(d) the oxygen present in the air

Answer: (a) the length of the day

5. The pre-sowing low temperature treatment of seeds is known as

(a) scarification

(b) electrophoresis

(c) vernalization

(d) abscission

Answer: (c) vernalization

6. The short day winter annual ‘Pansy’ belongs to the genus

(a) Iberis

(b) Viola

(c) Malva

(d) Papaver

Answer: (b) Viola

7. The effect of length of the day on plant growth is called

(a) photoperiodism

(b) phototropism

(c) photosynthesis

(d) chemotropism

Answer: (a) photoperiodism

8. Induction of flowering by low temperature in plants is

(a) vernalization

(b) photoperiodism

(c) pruning

(d) cryobiology

Answer: (a) vernalization

9. The pigment that absorbs the red and far-red light in plant is

(a) cytochrome

(b) xanthophylls

(c) phytochrome

(d) carotene

Answer: (c) phytochrome

10. Which of the following is not a hormone?

(a) GA3

(b) Ethylene

(c) Phytochrome

(d) Auxin

Answer: (c) Phytochrome

11. The wavelength absorbed by Pr form of phytochrome is

(a) 640nm

(b) 660nm

(c) 720nm

(d) 740nm

Answer: (b) 660nm

12. Which of the following statements is correct?

(a) the two forms of the phytochrome are photochemically inconvertible

(b) the Pfr form converts to Pr form slowly in darkness

(c) the dark conversion of Pfr and Pr form appears to be restricted to the dicotyledons only

(d) all of the above

Answer: (d) all of the above

13. The Pfr (far-red form of phytochrome) is required for flowering in

(a) both long and short day plants

(b) long day plants only

(c) short day plants only

(d) day neutral plants only

Answer: (a) both long and short day plants

14. Which of the following are day neutral plants?

(a) Mirabilis, Lycopersicum esculentum and Pisum sativum

(b) Glycine max and Mirabilis

(c) Lycopersicum esculentum and Beta vulgaris

(d) Glycine max and Pisum sativum

Answer: (a) Mirabilis, Lycopersicum esculentum and Pisum sativum

15. Which of the following is more sensitive to photoperiodic induction?

(a) young leaves

(b) mature leaves

(c) young buds

(d) partially mature leaves

Answer: (d) partially mature leaves

16. Vernalization is

(a) growth curve related to light

(b) effect of photoperiod on plant growth

(c) speeding up the availability ability to flower by low temperature treatment

(d) diurnal photoperiodicity

Answer: (c) speeding up the availability ability to flower by low temperature treatment

17. The response of different organisms to environmental rhythms of light and darkness is called

(a) vernalization

(b) phototaxis

(c) photoperiodism

(d) phototropism

Answer: (c) photoperiodism

 18. Photoperiodic stimulus is perceived by

(a) leaves

(b) flowers

(c) buds

(d) meristems

Answer: (a) leaves

 19. Which of the following plants is LDP?

(a) tobacco

(b) Glycine max

(c) Mirabilis jalapa

(d) Spinach

Answer: (d) Spinach

 20. Phytochrome was discovered by

(a) FW Went

(b) Borthwick and Hendricks

(c) F.F Blackman

(d) R Hills

Answer: (b) Borthwick and Hendricks

21. A pigment connected with both floral induction and seed germination is

(a) florigen

(b) chlorophyll

(c) plastocyanin

(d) phytochrome

Answer: (d) phytochrome

22. Phytochrome is found in

(a) algae

(b) fungi

(c) vascular cryptogams

(d) flowering plants

Answer: (d) flowering plants

 23. When the dark period of short day plant is interrupted by a brief exposure of light the plant?

(a) will not flower at all

(b) flowers immediately

(c) gives more flowers

(d) turns into a long day plant

Answer: (a) will not flower at all

 24. A chemical believed to be involved in flowering is

(a) gibberellins

(b) kinetin

(c) florigen

(d) IBA

Answer: (c) florigen

25. Which one shows red-far red interconversions?

(a) carotenoids

(b) cytochromes

(c) chlorophylls

(d) phytochrome

Answer: (d) phytochrome

 26. Flowering is induced by

(a) soil water content

(b) soil acidity

(c) photoperiod

(d) content of green pigment

Answer: (c) photoperiod

 27. Pigment involved in regulation/ photomorphogenetic response is

(a) phytochrome

(b) cytochrome

(c) xanthophylls

(d) chlorophyll b

Answer: (a) phytochrome

 28. Who discovered photoperiodism?

(a) Darwin

(b) Lysenko

(c) Arnon

(d) Gardner and Allard

Answer: (d) Gardner and Allard

 29. Which ones are long day plants?

(a) wheat, poppy, soyabean

(b) wheat, poppy beat

(c) wheat, oats soyabean

(d) wheat, xanthium, paddy

Answer: (b) wheat, poppy beat

 30. Pr state of phytochrome absorbs light wavelength of

(a) 660 nm

(b) 640nm

(c) 620nm

(d) 720nm

Answer: (b) 640nm

 31. Importance of day length in flowering of plants/ photoperiodism was first discovered in

(a) cotton

(b) tobacco

(c) Lemna

(d) Petunia

Answer: (b) tobacco

 32. Photoperiodic stimulus is perceived by

(a) shoot apex

(b) leaf

(c) flower

(d) young stem.

Answer: (a) shoot apex

33. Wheat is a……. day plant

(a) long

(b) shot

(c) only b

(d) none

Answer: (a) long

34. Phytochrome exists in…… forms

(a) 2

(b) 3

(c) 4

(d) none

Answer: (a) 2

35. When Pfr pigment absorbs…… wavelength, it is converted to Pr form.

(a) 660nm

(b) 740nm

(c) 640

(d) 620

Answer: (a) 660nm

36. The optimum range of temperature for vernalization is

(a) 1-7 degree centigrade

(b) 1-2 degree centigrade

(c) 1-3 degree centigrade

(d) none

Answer: (a) 1-7 degree centigrade

37. Low temperature treatment produces a hypothetical hormone called

(a) vernalin

(b) florigen

(c) auxin

(d) none

Answer: (a) vernalin

38. Which of the following is a long day plant?

(a) barley

(b) sorghum

(c) tobacco

(d) soybean

Answer: (a) barley

39. Which of the following is not a day neutral plant?

(a) roses

(b) pea

(c) tobacco

(d) tomatoes

Answer: (c) tobacco

40. Which of the following is a short night plant?

(a) barley

(b) larkspur

(c) sugar beet

(d) all the above

Answer: (d) all the above

41. Which of the following hormones can replace vernalisation?

(a) gibberelins

(b) auxin

(c) florigen

(d) all the above

Answer: (a) gibberelins

42. Maximum growth takes place in

(a) green light

(b) blue light

(c) ultraviolet

(d) red light

Answer: (d) red light

43. Florigen is synthesized in

(a) Stems

(b) leaves

(c) roots

(d) fruits

Answer: (b) leaves

44. A pigment responsible for light sensitivity in plants is

(a) Chlorophyll

(b) phytochrome

(c) carotene

(d) cytochrome

Answer: (b) phytochrome

45. Which of the following pigment is present in two forms?


(b) Florigen

(c) Phytochrome

(d) Venalin

Answer: (c) Phytochrome

46. Most of the plants are seasonal due to

(a) Photoperiodism

(b) phototropism

(c) photosynthesis

(d) photolysis

Answer: (a) Photoperiodism

47. Generally the internode of a plant elongates most in

(a) ultraviolet light

(b) infrared light

(c) blue wavelength of light

(d) complete spectrum of visible light

Answer: (c) blue wavelength of light

48. For germination of seed, which light is necessary?

(a) red light

(b) green light

(c) far red light

(d) blue light

Answer: (a) red light

49. Vernalization is done at

(a) Low temperature

(b) Low light intensity

(c) High temperature

(d) High light intensity

Answer: (a) Low temperature

50. The movement of organs in response to light is called

(a) Hydrotropism

(b) Thigmotropism

(c) Phototropism

(d) Geotropism

Answer: (c) Phototropism