1. Maize was first domesticated approximately how many years ago?
A. 2,000
B. 5,000
C. 9,000
D. 12,000
Answer: C. Domesticated by indigenous farmers in southern Mexico ~9,000 years ago from wild teosinte (Reddit)
2. Which part of the maize kernel contains the highest starch content (≈87.6 %)?
A. Pericarp
B. Germ
C. Aleurone
D. Endosperm
Answer: D. The endosperm of maize grain is ~87.6% starch (FAOHome)
3. The crude fat content of maize germ averages around:
A. 5%
B. 18%
C. 30–33%
D. 50%
Answer: C. Maize germ averages roughly 33% crude fat (Wikipedia)
4. Which amino acid is notably deficient in maize endosperm protein (zein)?
A. Leucine
B. Lysine
C. Glutamic acid
D. Cysteine
Answer: B. Zein proteins are low in lysine and tryptophan (FAOHome)
5. In 2022–23, which country produced the most maize?
A. China
B. Brazil
C. United States
D. Mexico
Answer: C. US led with ~346 million metric tons in 2022–23 (investopedia.com)
6. Globally in 2023–24, world maize production was forecast at approximately:
A. 1.16 billion t
B. 1.22 billion t
C. 1.30 billion t
D. 1.40 billion t
Answer: B. Forecast for global maize was ~1.223 billion tonnes (wsj.com)
7. What is the primary use of maize worldwide?
A. Human food
B. Seeds
C. Animal feed and ethanol
D. Beverage production
Answer: C. Most maize is used as livestock feed and for ethanol/biofuel production (Reddit, Reddit)
8. A single bushel of maize (~56 lb) can yield approximately how much ethanol?
A. 1.5 gal
B. 2.8–2.9 gal
C. 4.0 gal
D. 6.5 gal
Answer: B. Averaging 2.8–2.9 gallons ethanol per bushel (wired.com, Reddit)
9. Western corn rootworm larvae feed exclusively on maize for how many consecutive years?
A. 1
B. 2
C. 3
D. 4
Answer: B. Requires two successive maize seasons to complete its life cycle (Reddit)
10. Which transgene is common in Bt maize for insect resistance?
A. Cry1Ab
B. Cry3Bb1
C. Cry2Ae
D. Cry9C
Answer: B. Cry3Bb1 was among first Bt traits used; rootworm resistance showed early resistance in Iowa in 2009 (Reddit)
11. The Fall armyworm (Spodoptera frugiperda) was first detected outside the Americas in:
A. Africa (2010)
B. Africa (2016)
C. Asia (2018)
D. Europe (2019)
Answer: B. Detected in Africa in 2016, later spread into Asia by 2019 (Wikipedia)
12. Maize lethal necrosis (MLN) results from co-infection of maize chlorotic mottle virus and:
A. Tobacco mosaic virus
B. Maize dwarf mosaic virus
C. Rice yellow mottle virus
D. Wheat streak mosaic virus
Answer: B. MLND from MCMoV and a Potyvirus (often MDMV) (Wikipedia)
13. Grey Leaf Spot, a major foliar disease of maize, is caused by:
A. Fusarium graminearum
B. Cercospora zeae-maydis
C. Puccinia sorghi
D. Colletotrichum graminicola
Answer: B. GLS caused by Cercospora zeae-maydis or C. zeina (Wikipedia)
14. Maize dwarf mosaic virus (MDMV) is transmitted primarily by:
A. Aphids
B. Nematodes
C. Fungal spores
D. Seed contamination
Answer: A. Aphids transmit MDMV non-persistently within minutes (Wikipedia)
15. Which pest can cause yield losses of 20–100% by carrying Fusarium fungi into cobs?
A. Cutworm
B. Corn earworm
C. Maize stalk borer (Busseola fusca)
D. Maize aphid
Answer: C. Busseola fusca tunnels stalks and spreads Fusarium ear rot, causing major losses (wikifarmer.com, Wikipedia)
16. Maize endosperm protein fraction (zein) accounts for roughly what share of endosperm nitrogen?
A. 25%
B. 42%
C. 52%
D. 70%
Answer: C. Zein proteins make up ~52% of nitrogen in maize endosperm (FAOHome)
17. Which essential amino acid is especially low in standard maize protein?
A. Lysine
B. Methionine
C. Glutamine
D. Alanine
Answer: A. Lysine is limiting in common maize varieties (FAOHome)
18. What enhancement characterizes Quality Protein Maize (QPM)?
A. Higher oil
B. Increased calcium
C. Improved lysine and tryptophan
D. Drought tolerance
Answer: C. QPM varieties enriched in lysine and tryptophan to improve nutritional quality (Reddit, FAOHome)
19. Which breeding center operates the largest maize breeding programs globally?
A. IRRI
B. ICRISAT
C. CIMMYT
D. ICARDA
Answer: C. The International Maize and Wheat Improvement Center (CIMMYT) leads global maize breeding (FAOHome, wikifarmer.com)
20. Orange maize, biofortified with provitamin A, was shown to be efficacious in children living in:
A. India
B. Zambia
C. Guatemala
D. Mexico
Answer: B. Trials in Zambian children showed biofortified maize improved vitamin A status (pmc.ncbi.nlm.nih.gov, pubmed.ncbi.nlm.nih.gov)
21. Which of the following is NOT a major use of maize starch?
A. Corn syrup production
B. Brewing beer
C. Industrial bioplastics
D. Animal feed binder
Answer: B. Beer is brewed primarily from barley, not starch-rich maize; maize starch used for syrup, bioplastics, feed (Reddit)
22. Which maize disease first emerged in East Africa in 2010 and threatens seed system resilience?
A. Northern corn leaf blight
B. Maize streak virus
C. Maize lethal necrosis disease
D. Grey leaf spot
Answer: C. Maize lethal necrosis (MLND) first observed in East Africa around 2010 (wikifarmer.com, Wikipedia, Wikipedia)
23. Maize grey leaf spot lesions typically run:
A. Across leaf veins
B. Parallel to veins
C. In concentric rings
D. Randomly distributed
Answer: B. Necrotic lesions are rectangular and parallel to veins (Wikipedia, Wikipedia)
24. Which pest attacks the silks and ears of maize, reducing pollination and grain set?
A. Corn earworm (Helicoverpa zea)
B. Stalk borer
C. Maize aphid
D. Cutworm
Answer: A. Corn earworm larvae damage silks and cobs, interfering with pollination (wikifarmer.com, Reddit)
25. Grey leaf spot pathogen survives primarily on:
A. Previous crop residue
B. Seed coat
C. Root nodules
D. Soil fungus
Answer: A. Cercospora survives in crop debris; rotation and residue management help (Wikipedia)
26. Cutworms most commonly damage maize at which stage?
A. Germination
B. Vegetative
C. Flowering
D. Harvest
Answer: A. Cutworms feed on young seedlings, cutting stems near the soil (wikifarmer.com)
27. What proportion of maize kernel protein is in the germ?
A. <5%
B. ~8%
C. ~18%
D. ~40%
Answer: C. Germ protein content is ~18.4%, higher than endosperm (~8%) (FAOHome)
28. What percentage of total maize production is typically used as livestock feed globally?
A. ~25%
B. ~40%
C. ~60–70%
D. ~90%
Answer: C. Approximately 60–70% of maize is used for feed and ethanol (Reddit, Reddit)
29. Maize stalk borer (Busseola fusca) primarily tunnels into:
A. Roots
B. Leaves
C. Stalks
D. Ears only
Answer: C. Larvae bore into stalks, damaging vascular system (Wikipedia)
30. Which virus alone can cause 75% yield loss in late-planted maize?
A. Tobacco streak virus
B. Maize dwarf mosaic virus (MDMV)
C. Sugarcane mosaic virus (SCMV)
D. Bean common mosaic virus
Answer: B. MDMV may cause up to 75% loss if infection occurs early (esp. in certain hybrids) (Wikipedia, Wikipedia)
31. What is a key benefit of hybrid maize varieties?
A. Perennial growth
B. 100% lysine-rich
C. Uniform maturity and higher yields
D. Spontaneous root branching
Answer: C. Hybrids give uniformity, lodging resistance, higher yields (FAOHome)
32. Which part of maize contains high levels of hemicellulose (~67%)?
A. Endosperm
B. Germ
C. Pericarp (seed coat)
D. Embryo
Answer: C. The pericarp is high in crude fiber (~87%) dominated by hemicellulose (~67%) (FAOHome)
33. Brace roots in maize chiefly assist with:
A. Nutrient uptake only
B. Worm resistance
C. Structural anchorage and water uptake
D. Tassel development
Answer: C. Brace roots help support stalks and aid water/nutrient uptake (arxiv.org, Wikipedia)
34. Which major US pest required two consecutive maize years to complete lifecycle?
A. Western corn rootworm
B. Fall armyworm
C. Corn earworm
D. Maize aphid
Answer: A. Western corn rootworm needs two years of maize to thrive (Reddit, Reddit)
35. Orange maize trial in Zambian children showed roughly what absorption efficiency of provitamin A dose?
A. ~40%
B. ~60%
C. ~80%
D. 95%∼80%) (pmc.ncbi.nlm.nih.gov)
Answer: C. Orange maize absorption and retention was high (
36. Grey leaf spot lesions turn into necrotic rectangles aligned how?
A. Horizontally
B. Vertically
C. Diagonally
D. Randomly oriented
Answer: B. GLS lesions are long, rectangular, between veins—vertical alignment (Wikipedia)
37. The maize weevil (Sitophilus zeamais) primarily infests maize in which stage?
A. Live plants
B. Plant roots
C. Stored grain
D. Tassels
Answer: C. Maize weevil attacks both standing crops and stored cereals of all types (Wikipedia)
38. Maize lethal necrosis is most prevalent in:
A. Europe
B. North America
C. East Africa & Southeast Asia
D. Australia
Answer: C. MLND reported predominantly in East Africa and Southeast Asia (Wikipedia)
39. Large outbreaks of grey leaf spot are often linked to which farming practice?
A. Deep plowing
B. Crop rotation with soy
C. No-till and residue retention
D. High nitrogen on sandy soil
Answer: C. No-till systems with residue exacerbate Cercospora survival (Wikipedia)
40. Corn earworm (Helicoverpa zea) feeds mainly on:
A. Roots
B. Silks, leaves, and ears
C. Stalk nodes
D. Brace roots
Answer: B. Attacks silks/ears, affecting grain set/pollination (wikifarmer.com, arxiv.org)
41. Nutrition-wise, maize kernel germ provides highest contributions to:
A. Starch energy
B. Protein and fat
C. Fiber
D. Water content
Answer: B. Germ is rich in fat (~33%) and higher-quality protein (~18%) (Reddit)
42. Maize seed dressing treatments can control early injuries by:
A. Cutworms
B. Fall armyworm
C. Stem borer
D. Aphids
Answer: A. Treated seeds help mitigate damage from cutworms at seedling stage (wikifarmer.com)
43. Global maize harvest decline in 2023–24 was due to:
A. Rodent outbreaks
B. Soil erosion
C. Drought and disease in southern hemisphere
D. Trade restrictions
Answer: C. IGC lowered production forecast due to Southern Hemisphere droughts and disease (wsj.com)
44. Which is NOT typically an essential amino acid deficiency in maize?
A. Lysine
B. Tryptophan
C. Methionine
D. Valine
Answer: D. Valine is not limiting; lysine/tryptophan are the most limiting (FAOHome)
45. Biofortified orange maize in Zambia was compared against which control group?
A. Sorghum
B. White maize plus placebo oil
C. Vitamin A capsule only
D. Oat cereal
Answer: B. Compared to white maize diet with placebo oil and a positive (VA-supplement) control group (pubmed.ncbi.nlm.nih.gov, pmc.ncbi.nlm.nih.gov)
46. Which farming technique increased maize silking failure due to Earworm damage?
A. GMO adoption
B. Left unmanaged silage
C. Dense planting without irrigation
D. Infestation of corn earworm on silks
Answer: D. Damage to maize silks impairs pollination and yields (Reddit)
47. Economic losses from western corn rootworm and corn earworm in the United States exceed:
A. $10 million/year
B. $250 million/year
C. $1 billion/year
D. $5 billion/year
Answer: C. Each pest has caused annual losses exceeding $1 billion in the US (Reddit)
48. Among maize components, which layer contains ~19% protein and high fibre?
A. Coleoptile
B. Aleurone layer
C. Husk
D. Kernel tip cap
Answer: B. The aleurone layer is high in protein (~19%) and fibre (FAOHome, Reddit)
49. The physical structure known as "brace roots" are most important for:
A. Flowering initiation
B. Grain moisture retention
C. Mechanical stability under wind
D. Seed germination
Answer: C. Brace roots externally provide anchorage and resource uptake in tall maize plants (arxiv.org)
50. Which insect pest can overwinter in the soil, emerging to cut down young maize plants?
A. Spider mite
B. Cutworm
C. Maize borer
D. Armyworm
Answer: B. Cutworms overwinter and feed on seedlings at soil level (wikifarmer.com)
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 on maize (Zea mays)){kind=link}
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