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Covers topics from Horticulture Science:: Agri Quiz: Horticulture: Onion MCQ
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Multiple Choice Questions (MCQs) with instant answers and explanations.
1. What is the botanical name of onion?
Allium sativum
Allium cepa
Allium tuberosum
Allium ascalonicum
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Correct Answer: Allium cepa The correct botanical name for onion is Allium cepa. It belongs to the family Alliaceae.
2. To which family does the onion belong?
Solanaceae
Cruciferae
Alliaceae
Leguminosae
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Correct Answer: Alliaceae Onion belongs to the family Alliaceae, which also includes other bulbous plants like garlic and leeks.
3. What is the primary place of origin of the onion?
Mediterranean region
South America
Central Asia
India
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Correct Answer: Central Asia The primary place of origin of the onion is considered to be Central Asia, from where it spread to other parts of the world.
4. What type of inflorescence is found in onion?
Raceme
Spike
Umbel
Panicle
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Correct Answer: Umbel The onion plant has an umbel type of inflorescence, characterized by a cluster of flowers arising from a single point on the stem.
5. What is the chromosome number (2n) of onion?
14
16
20
22
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Correct Answer: 16 The diploid chromosome number (2n) in onion is 16. This is important for genetic studies and breeding.
6. Which part of the onion plant is edible?
Leaves
Roots
Modified stem/bulb
Flower
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Correct Answer: Modified stem/bulb The edible part of the onion plant is the modified stem, which forms the bulb. This bulb stores food reserves.
7. What type of fruit does the onion produce?
Berry
Drupe
Capsule
Pod
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Correct Answer: Capsule The onion produces a capsule fruit, which is a dry fruit that splits open to release seeds.
8. Which enzyme is present in onion?
Amylase
Catalase
Allinase
Protease
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Correct Answer: Allinase Onion contains an enzyme called allinase. This enzyme is responsible for the formation of the volatile compounds that cause tearing when onions are cut.
9. What type of pollination occurs in onions?
Self-pollination
Cross-pollination
Both self and cross
Apomixis
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Correct Answer: Cross-pollination Onions are primarily cross-pollinated. Insects, mainly bees, facilitate the transfer of pollen between different onion plants.
10. Onion is a good source of which nutrients?
Iron and Vitamin A
Phosphorus Calcium and Vitamin B & C
Sodium and Potassium
Vitamin D and E
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Correct Answer: Phosphorus Calcium and Vitamin B & C Onions are a good source of phosphorus, calcium, and vitamins B and C, contributing to their nutritional value.
11. Which country is the largest producer of onions in the world?
India
United States
China
Brazil
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Correct Answer: China China is currently the largest producer of onions globally, followed by India.
12. Which country is the largest exporter of onions?
India
Netherlands
China
United States
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Correct Answer: Netherlands The Netherlands is the largest onion-exporting country in the world, playing a significant role in the global onion trade.
13. Which Indian state is the leading producer of onions?
Gujarat
Maharashtra
Madhya Pradesh
Karnataka
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Correct Answer: Maharashtra Maharashtra is the leading onion-producing state in India, contributing substantially to the country's total onion output.
14. What is the most suitable climate for onion cultivation?
Hot and humid
Warm and dry
Cool
Tropical
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Correct Answer: Cool Onions thrive in a cool climate, which is why they are often grown as a Rabi (winter) crop in many regions.
15. What is the ideal temperature range for onion vegetative growth?
5-10°C
13-24°C
25-30°C
30-35°C
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Correct Answer: 13-24°C The ideal temperature range for the vegetative growth of onions is 13-24°C. This temperature supports optimal leaf and stem development.
16. What is the optimal temperature range for onion bulb formation?
10-15°C
15.5-25.1°C
20-30°C
25-35°C
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Correct Answer: 15.5-25.1°C For proper bulb formation, onions require a temperature range of 15.5-25.1°C. This temperature range ensures healthy bulb development.
17. What is the suitable soil pH range for onion cultivation?
4.5-5.5
5.5-6.5
6.5-7.5
7.5-8.5
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Correct Answer: 5.5-6.5 Onions prefer a slightly acidic to neutral soil with a pH range of 5.5-6.5. This pH level allows for optimal nutrient availability.
18. Onion is primarily grown as which season crop in India?
Kharif
Rabi
Zaid
All of the above
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Correct Answer: Rabi In India, onion is primarily grown as a Rabi (winter) crop, though it can also be cultivated in the Kharif (monsoon) season in some regions.
19. On the basis of seed production, the onion is classified as a ______ vegetable.
Annual
Biennial
Perennial
Triennial
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Correct Answer: Biennial Based on its seed production cycle, the onion is considered a biennial vegetable, as it typically takes two years to complete its life cycle from seed to seed.
20. On the basis of bulb formation, the onion is classified as a ______ vegetable.
Annual
Biennial
Perennial
Triennial
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Correct Answer: Annual Based on bulb formation, the onion is classified as an annual vegetable, as the bulb develops and is harvested within one growing season.
21. Which flowering stage is found in onion?
Protogyny
Protoandry
Dichogamy
Homogamy
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Correct Answer: Protoandry Onions exhibit protoandry, a condition where the male parts (stamens) mature before the female parts (pistils), promoting cross-pollination.
22. Onion is generally considered a ______ day plant.
Short
Long
Day-neutral
Intermediate
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Correct Answer: Long Onion is generally considered a long-day plant, meaning it requires longer day lengths to initiate bulb formation in many varieties.
23. Who is known as 'Mr. Onion'?
Dr. M.S. Swaminathan
Dr. Norman Borlaug
Dr. H.A. Jones
Dr. B.P. Pal
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Correct Answer: Dr. H.A. Jones Dr. H.A. Jones is known as 'Mr. Onion' for his significant contributions to onion research and breeding.
24. What is the name of India's largest onion market?
Azadpur Mandi
Pimpalgaon Baswant
Lasalgaon Mandi
Hubballi Market
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Correct Answer: Lasalgaon Mandi Lasalgaon Mandi, located in Maharashtra, is the largest onion market in India.
25. Which vegetable is the most exported vegetable in India?
Tomato
Potato
Onion
Cabbage
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Correct Answer: Onion Onion is one of the most exported vegetables from India, contributing significantly to the country's agricultural exports.
26. What is the botanical name of underground onion/multiple onion?
Allium cepa var. viviparum
Allium cepa var. aggregatum
Allium sativum
Allium fistulosum
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Correct Answer: Allium cepa var. aggregatum The underground onion, also known as the multiplier onion, is botanically classified as Allium cepa var. aggregatum.
27. Where is the Directorate of Onion and Garlic Research (DOGR) located?
New Delhi
Pune
Hyderabad
Karnal
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Correct Answer: Pune The Directorate of Onion and Garlic Research (DOGR) is located at Rajgurunagar, Pune, in Maharashtra, India.
28. Varieties named 'Bhima' are developed from which institute?
IARI
IIHR
DOGR
NHRDF
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Correct Answer: DOGR Varieties with the prefix 'Bhima' have been developed by the Directorate of Onion and Garlic Research (DOGR), Pune.
29. Which type of onion is known for its high pungency?
White onion
Yellow onion
Red onion
Pink onion
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Correct Answer: Red onion Red onions are generally known for their strong, pungent flavor compared to other varieties.
30. Which type of onions are best suited for processing and drying?
Red onions
Yellow onions
White onions
Pink onions
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Correct Answer: White onions White onions are preferred for processing and drying due to their high solid content and mild flavor.
31. At which stage is the onion crop typically harvested?
Flowering stage
Bulb formation stage
Neck fall stage
Seed maturity stage
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Correct Answer: Neck fall stage Onions are typically harvested at the neck fall stage, when the tops of the plants begin to bend or fall over, indicating maturity.
32. Which chemical was previously used to prevent germination in stored onions but is now banned?
CIPC
MH (Malic Hydrazide)
NAA
GA3
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Correct Answer: MH (Malic Hydrazide) Malic Hydrazide (MH) was previously used to inhibit sprouting in stored onions, but its use has been banned in India. CIPC is now used.
33. Which chemical causes tears while cutting onions?
Allicin
Capsaicin
Propanethial S-oxide
Allyl Propyl Disulfide
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Correct Answer: Allyl Propyl Disulfide The compound responsible for the tears produced while cutting onions is Allyl Propyl Disulfide. It is a volatile sulfur compound.
34. What is the major weed in onion fields?
Cyperus rotundus
Chenopodium album
Allium sp.
Parthenium hysterophorus
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Correct Answer: Allium sp. A common and troublesome weed in onion fields is often another Allium species, making it difficult to control selectively.
35. What is the water requirement of the onion crop?
200-300 mm
300-400 mm
500-600 mm
700-800 mm
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Correct Answer: 500-600 mm The onion crop requires a water supply of 500-600 mm, depending on the climate, soil type, and growth stage.
36. What genetic condition is commonly found in onion plants, influencing breeding?
Self-compatibility
Genetic male sterility
Apomixis
Polyploidy
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Correct Answer: Genetic male sterility Genetic male sterility is a feature found in onion, and it's very useful in hybrid seed production.
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37. Which herbicide is commonly used for weed control in onion?
Glyphosate
Atrazine
Fluchloralin
Pendimethalin
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Correct Answer: Fluchloralin Fluchloralin is a pre-emergence herbicide commonly used to control weeds in onion cultivation.
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