🧬 Biology · Topic 10 of 10
Start with the study notes on Crop Production, Conservation & Environment (definitions, examples and a quick revision), then work through 60 practice questions, each with the correct answer and a clear explanation of why it is right. When you are ready, take this topic as an interactive quiz to test yourself.
Topic overview
A crop is a large number of plants of one kind grown by people.
Ploughing (tilling) loosens and turns the soil, letting in air and helping roots grow.
Sowing is placing seeds in the soil. A seed drill sows seeds evenly at the right depth.
These replace the nutrients that crops use up.
Example: Vermicompost is made by earthworms from waste. Earthworms are the “farmer's friend” because they loosen and enrich the soil.
Irrigation is supplying water to crops at regular intervals, from wells, canals, rivers or dams.
Weeds are unwanted plants that steal water, light and nutrients from the crop. They are removed by hand, with tools, or with weedicides. Pesticides kill insect pests, but must be used carefully.
Animal husbandry is raising animals for food and other products.
Examples:
Deforestation is clearing forests for farms, towns, roads and industry.
Example: In the Chipko Movement of the 1970s, villagers in Uttarakhand hugged trees to stop them being cut.
Biodiversity is the variety of plants, animals and microbes in an area.
Example: The Red Data Book records the species at risk.
Example: Project Tiger (1973) set up tiger reserves to save the tiger.
| Misconception | Correct understanding |
|---|---|
| Wheat is a kharif crop. | Wheat is a rabi (winter) crop; rice is a kharif (rainy-season) crop. |
| More fertiliser always means a better crop. | Overuse damages the soil and pollutes rivers and lakes. |
| All insects in a field are pests. | Bees and many insects help crops; pesticides can kill them too. |
| Endangered and extinct mean the same. | Endangered species still survive but are at risk; extinct species are gone forever. |
| Cutting forests only affects trees. | It causes soil erosion, less rain and loss of wildlife. |
Give one kharif and one rabi crop.
Rice (kharif) and wheat (rabi).
Why is the soil ploughed before sowing?
To loosen it, so that air gets in and roots grow easily.
Why is drip irrigation good for dry areas?
It drips water straight onto the roots, so very little is wasted.
Why are grains dried before storage?
Moisture would let microbes and pests spoil them.
How does growing gram help the soil?
Its root nodules hold bacteria that add nitrogen to the soil.
What is apiculture?
Bee-keeping, for honey and wax.
Name two harmful effects of deforestation.
Soil erosion and loss of wildlife habitat (also less rainfall).
Where is the one-horned rhinoceros protected?
In Kaziranga National Park, Assam.
Key takeaway: Good farming feeds us, but forests, soil, water and wildlife must be protected so the Earth can keep feeding future generations.
Notes written by Velnov for Class 6–8 students, following the topics of the NCERT science syllabus.
Q1. easy
When plants of the same kind are grown on a large scale, they are called a:
Answer: A — Crop
A crop is a large number of plants of one kind grown and cultivated by people, such as wheat, rice or cotton grown in a field.
Q2. easy
Crops grown in the RAINY season (June to September) are called:
Answer: A — Kharif crops
Kharif crops such as paddy, maize, cotton and groundnut are sown at the beginning of the monsoon and harvested in autumn. They need plenty of water.
Q3. medium
Crops grown in the WINTER season (October to March) are called:
Answer: A — Rabi crops
Rabi crops such as wheat, gram, peas and mustard are sown in winter and harvested in spring. They need less water than kharif crops.
Q4. medium
The loosening and turning of the soil before sowing is called:
Answer: A — Ploughing (tilling)
Ploughing loosens the soil so that roots can breathe and penetrate easily, and it brings nutrient-rich soil to the top. It is done with a plough or a tractor-drawn cultivator.
Q6. medium
The placing of seeds in the soil is called:
Answer: A — Sowing
Seeds may be sown by hand or with a seed drill. Good-quality, healthy seeds sown at the correct depth and spacing give a better crop.
Q8. medium
Substances added to the soil to supply nutrients to plants are called:
Answer: A — Manures and fertilisers
Manures and fertilisers replace the nitrogen, phosphorus and potassium that crops remove from the soil, keeping it fertile for the next crop.
Q10. medium
Which of these is an ADVANTAGE of manure over chemical fertilisers?
Answer: A — Manure improves soil texture and does not harm the environment
Manure adds humus that improves soil structure and its ability to hold water and air, and it is eco-friendly. Chemical fertilisers act faster but can damage soil and water if overused.
Q12. medium
Which modern irrigation method delivers water DROP by DROP to the roots, saving water?
Answer: A — Drip irrigation
Drip irrigation uses narrow pipes with tiny openings to drip water directly at the base of each plant. Very little water is wasted, so it is ideal for dry regions.
Q14. medium
Unwanted plants that grow along with a crop are called:
Answer: A — Weeds
Weeds compete with the crop for water, nutrients, light and space, reducing the yield. Their removal is called weeding.
Q16. medium
The cutting and gathering of a mature crop is called:
Answer: A — Harvesting
Harvesting is done by hand with a sickle or by a machine called a harvester. It marks the end of the crop's growth in the field.
Q18. medium
A machine that both harvests and threshes the crop is called a:
Answer: A — Combine (combine harvester)
The combine harvester cuts, threshes and cleans the grain in a single operation, saving a great deal of time and labour on large farms.
Q20. medium
The rearing of animals on a large scale for food and other products is called:
Answer: A — Animal husbandry
Animal husbandry includes rearing cattle, buffaloes, goats, poultry and fish for milk, meat, eggs and other products. It complements crop farming.
Q22. medium
The rearing of silkworms to obtain silk is called:
Answer: A — Sericulture
Sericulture is silk farming. Silkworms are fed mulberry leaves, and the fine thread from their cocoons is unwound to make silk.
Q24. medium
The variety of living organisms found in an area is called its:
Answer: A — Biodiversity
Biodiversity is the total range of plants, animals and microorganisms in a region. High biodiversity keeps ecosystems healthy and stable.
Q26. medium
Which of these is a HARMFUL effect of deforestation?
Answer: A — Soil erosion, less rainfall, and loss of wildlife habitat
Without tree roots to bind it, soil is washed or blown away. Fewer trees mean less transpiration and rainfall, higher temperatures and homeless wildlife.
Q28. medium
The protection and careful management of natural resources is called:
Answer: A — Conservation
Conservation means using resources wisely and protecting them so that they remain available for future generations. Forests, water and wildlife all need conservation.
Q30. medium
A species that has completely died out and no longer exists is called:
Answer: A — Extinct
The dinosaurs and the dodo are extinct - not a single individual survives anywhere. Extinction is permanent, which is why saving endangered species matters.
Q32. medium
A protected area where wild animals live in their natural habitat and hunting is banned is a:
Answer: A — Wildlife sanctuary
In a wildlife sanctuary, animals are protected in their natural surroundings and killing or capturing them is prohibited. People may enter with permission.
Q34. medium
A large area that protects biodiversity and includes national parks, sanctuaries and human settlements is called a:
Answer: A — Biosphere reserve
A biosphere reserve conserves the biodiversity of a whole region, allowing traditional human life to continue alongside protected wildlife. Nilgiri and Sundarbans are examples.
Q36. medium
The one-horned rhinoceros is protected mainly in which Indian national park?
Answer: A — Kaziranga (Assam)
Kaziranga National Park in Assam is famous for the great one-horned rhinoceros. Its protection has brought this endangered animal back from the brink.
Q38. medium
Which of these is a way to conserve WATER?
Answer: A — Rainwater harvesting and drip irrigation
Collecting rainwater to recharge the ground, using efficient drip irrigation and fixing leaks all help conserve our limited fresh water.
Q40. medium
Reforestation is important because forests:
Answer: A — Give oxygen, hold soil, bring rain and shelter wildlife
Forests release oxygen, absorb carbon dioxide, prevent soil erosion, help rainfall and provide homes for countless species, so replanting them benefits the whole environment.
Q42. medium
Which of these is a RENEWABLE natural resource?
Answer: A — Forests (if replanted)
Forests, water, wind and sunlight are renewable - they can be replaced or are continuously available. Coal, petroleum and minerals are non-renewable.
Q44. medium
The seasonal movement of animals such as birds from one region to another is called:
Answer: A — Migration
Migratory birds travel long distances to escape harsh weather or to find food and breeding grounds. Wetlands where they rest need protection.
Q46. medium
Growing a legume crop like gram or beans in rotation improves the soil because these plants:
Answer: A — Host Rhizobium bacteria that fix nitrogen in the soil
Rhizobium in the root nodules of legumes converts atmospheric nitrogen into compounds the soil can use, so less fertiliser is needed for the next crop.
Q48. medium
Chemicals sprayed to kill insects and pests on crops are called:
Answer: A — Pesticides
Pesticides protect crops from insect attack, but their overuse harms useful insects, pollutes the environment and leaves residues on food, so they must be used carefully.
Q50. medium
Green Revolution in India refers to:
Answer: A — The large increase in food-grain production using high-yielding seeds and modern methods
From the 1960s, high-yielding varieties, irrigation, fertilisers and machinery greatly raised wheat and rice output, making India self-sufficient in food grains.
Q52. medium
Vermicomposting is the making of compost using:
Answer: A — Earthworms
Earthworms feed on organic waste and turn it into nutrient-rich vermicompost. This is an eco-friendly, low-cost way to recycle kitchen and farm waste.
Q54. medium
Which practice helps conserve SOIL and prevent erosion on hilly land?
Answer: A — Terrace farming and planting trees
Cutting steps (terraces) into a hillside slows the flow of water so it cannot wash away the soil, and tree roots bind the soil in place.
Q56. medium
Which of these is a good way for students to help the environment?
Answer: A — Planting trees, saving water and electricity, and reducing waste
Small everyday actions - planting trees, switching off unused lights and taps, avoiding plastic and segregating waste - add up to a real difference for the environment.
Q58. medium
Which overall statement about crop production and conservation is CORRECT?
Answer: A — Good farming needs soil preparation, sowing, nutrients, irrigation, protection and harvesting - and natural resources must be conserved for the future
This sums up the topic: raising a crop involves a sequence of steps from ploughing to storage; animal husbandry adds to our food; and forests, water, soil and wildlife must all be conserved so that the Earth can support future generations.
Q59. medium
Growing two or more crops together in the same field at the same time is called:
Answer: A — Mixed cropping
Mixed cropping, such as growing wheat with gram, reduces the risk of total crop failure and uses the soil and space more efficiently. If one crop fails, the other may still give a yield.
Q5. hard
Why is loosening the soil by ploughing important?
Answer: A — It allows air into the soil and helps roots grow and absorb nutrients easily
Loose soil holds air needed by roots and soil organisms, lets roots spread and breathe, and helps water and nutrients move freely.
Q7. hard
A tool used for sowing seeds uniformly at the correct depth is the:
Answer: A — Seed drill
A seed drill, attached to a tractor, sows seeds at even spacing and depth and covers them with soil. This saves seed and ensures uniform germination.
Q9. hard
The natural substance made by decomposing plant and animal waste, added to enrich soil, is called:
Answer: A — Manure
Manure is decomposed organic matter such as cow dung and compost. It improves soil texture and its water-holding capacity, besides adding nutrients.
Q11. hard
The supply of water to crops at regular intervals is called:
Answer: A — Irrigation
Irrigation provides the water crops need to grow. Sources include wells, tube wells, ponds, lakes, rivers, dams and canals.
Q13. hard
The sprinkler system of irrigation is especially useful for:
Answer: A — Sandy and uneven land where water needs to be spread like rain
Sprinklers spray water through rotating nozzles, imitating rainfall. They suit uneven or sandy soils where flooding would waste water or wash away seeds.
Q15. hard
Chemicals used to control or kill weeds are called:
Answer: A — Weedicides (herbicides)
Weedicides such as 2,4-D are sprayed to kill weeds without harming the crop. Weeds can also be removed by hand, by tools, or by ploughing before sowing.
Q17. hard
The process of separating grain seeds from the harvested stalks is called:
Answer: A — Threshing
Threshing beats or rubs the harvested crop to free the grain from the chaff and stalks. A combine harvester both harvests and threshes in one operation.
Q19. hard
Grains meant for storage must first be DRIED because:
Answer: A — Moisture would allow microorganisms and pests to spoil them
Damp grains are quickly attacked by fungi, bacteria and insects. Proper drying in the sun before storage keeps them safe for months.
Q21. hard
The rearing of honey bees for honey and wax is called:
Answer: A — Apiculture
Apiculture is bee-keeping. Bees are reared in artificial hives to obtain honey and beeswax, and they also pollinate nearby crops.
Q23. hard
The rearing of fish on a large scale for food is called:
Answer: A — Pisciculture
Pisciculture, or fish farming, raises fish in ponds and tanks. It is an important source of protein and income in many parts of India.
Q25. hard
The gradual disappearance of forests due to human activities is called:
Answer: A — Deforestation
Deforestation is the clearing of forests for farming, building, roads and industry. It reduces biodiversity, causes soil erosion and increases carbon dioxide in the air.
Q27. hard
The planting of trees to create new forests is called:
Answer: A — Afforestation
Afforestation restores green cover. Replanting trees where a forest once stood is called reforestation. Both help fight the effects of deforestation.
Q29. hard
A species whose numbers have fallen so low that it may soon become extinct is called:
Answer: A — An endangered species
The tiger, one-horned rhinoceros, Asiatic lion and great Indian bustard are endangered. Special protection is needed to save them from extinction.
Q31. hard
Species found ONLY in a particular area and nowhere else are called:
Answer: A — Endemic species
Endemic species are native to a single region. The Asiatic lion (Gir forest) and the Nilgiri tahr are endemic to particular parts of India.
Q33. hard
A large protected area for the whole ecosystem - plants, animals and landscape - where human activity is strictly limited is a:
Answer: A — National park
National parks protect entire ecosystems. No private activity such as grazing, farming or cutting wood is allowed. Jim Corbett and Kaziranga are famous Indian national parks.
Q35. hard
Project Tiger was launched in India to:
Answer: A — Protect tigers and increase their numbers
Project Tiger, started in 1973, set up tiger reserves to protect the endangered tiger and its habitat. It has helped stabilise and increase tiger numbers.
Q37. hard
The Asiatic lion is now found in the wild only in:
Answer: A — The Gir forest of Gujarat
The Gir forest is the last natural home of the Asiatic lion. Careful protection has raised its numbers from a few dozen to several hundred.
Q39. hard
The 3 R's that help protect the environment stand for:
Answer: A — Reduce, Reuse, Recycle
Reducing what we use, reusing items and recycling waste all cut the demand on natural resources and reduce pollution.
Q41. hard
The 'Chipko Movement' is famous for:
Answer: A — Villagers hugging trees to prevent them from being cut down
In the Chipko Movement of the 1970s, villagers in Uttarakhand embraced trees to stop them being felled, drawing worldwide attention to forest conservation.
Q43. hard
The Red Data Book is a record of:
Answer: A — Endangered species of plants and animals
The Red Data Book keeps a record of all species at risk. It helps scientists and governments plan conservation for endangered plants and animals.
Q45. hard
Growing DIFFERENT crops in a field in successive seasons to keep the soil fertile is called:
Answer: A — Crop rotation
Crop rotation, especially growing a legume between cereal crops, restores soil nitrogen naturally and reduces the build-up of pests and diseases.
Q47. hard
The excessive use of chemical fertilisers is harmful because it:
Answer: A — Damages soil fertility over time and pollutes water bodies
Overuse makes the soil acidic or saline and kills useful soil organisms. Rain washes the excess into rivers and lakes, causing algal blooms and killing fish.
Q49. hard
Why is the overuse of pesticides a concern?
Answer: A — They kill helpful insects, pollute water and food, and harm human health
Pesticides do not distinguish between pests and helpful insects like bees. Their residues accumulate in the food chain, harming birds, animals and people.
Q51. hard
The White Revolution in India is associated with a large increase in the production of:
Answer: A — Milk
The White Revolution, or Operation Flood, made India the world's largest milk producer through dairy cooperatives. It is linked with Dr Verghese Kurien.
Q53. hard
Earthworms are called the 'farmer's friend' because they:
Answer: A — Loosen and aerate the soil and enrich it with their castings
As earthworms burrow, they loosen and mix the soil, letting in air and water. Their nutrient-rich waste (castings) makes the soil more fertile.
Q55. hard
Overgrazing by animals leads to:
Answer: A — Loss of vegetation cover, soil erosion and desertification
When too many animals graze an area, the grass cannot recover, the bare soil erodes, and fertile land can gradually turn into desert.
Q57. hard
Why is maintaining biodiversity important for agriculture?
Answer: A — It keeps ecosystems balanced - pollinators, natural pest control and soil organisms all support crops
Bees and other insects pollinate crops, birds and predators control pests, and soil organisms recycle nutrients. Losing this variety would make farming far harder.
Q60. hard
Why is stubble (leftover crop) burning after harvest discouraged?
Answer: A — It causes heavy air pollution and destroys useful soil organisms and nutrients
Burning crop residue releases large amounts of smoke and particulate matter into the air and kills the microbes and burns the organic matter that keep the soil fertile. Mixing the stubble back into the soil is far better.
Practice “Crop Production, Conservation & Environment” as a quiz