GK: Class 12 General Q&A · Page 178
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What are cotyledons?
Cotyledons are the embryonic seed leaves present in the seed of a plant, serving as the first leaves to appear during germination and playing a crucial role in early seedling nutrition. These specialized structures store food reserves—primarily proteins, carbohydrates, and lipids—that nourish the developing embryo until the seedling can produce its own food through photosynthesis. In some plants, cotyledons emerge above ground and turn green to photosynthesize (epigeal germination
- GeneralClass 12All
Cycas and Pinus belong to which group of plant kingdom?
Cycas and Pinus both belong to the group Gymnosperms, which are seed-bearing vascular plants characterized by having "naked seeds" that are not enclosed within a fruit. The term gymnosperm literally means "naked seed" in Greek, referring to the fact that their seeds develop on the surface of cone scales or specialized structures rather than being protected inside an ovary. Cycas represents the cycads, an ancient group with palm-like appearance and large compound leaves, while Pinus (pine tree
- GeneralClass 12All
Give two examples of algae.
Spirogyra and Chlamydomonas are two common examples of algae that demonstrate the diversity within this group of photosynthetic organisms. Spirogyra is a filamentous green alga often found in freshwater ponds and slow-moving streams, recognizable by its ribbon-like spiral chloroplasts that give it a distinctive appearance under the microscope. Chlamydomonas, on the other hand, is a unicellular green alga that moves using two flagella and is widely studied in laboratory settings to understand
- GeneralClass 12All
What is pasturage and how is it important?
Pasturage refers to the grazing lands, grasslands, meadows, and fodder resources available for livestock to graze freely and obtain their nutritional requirements naturally from growing vegetation. These areas include natural grasslands, cultivated pastures with nutritious grass species, fallow agricultural lands with spontaneous vegetation growth, and communal grazing grounds traditionally used by livestock herders. Quality pasturage provides cattle, sheep, goats, and other ruminants with co
- GeneralClass 12All
What are the components of cattle feed?
Cattle feed comprises two main categories: roughage and concentrates, which must be balanced to meet the nutritional requirements for maintenance, growth, reproduction, and milk or meat production. Roughage forms the bulk of cattle feed (60-70% by volume) and includes fibrous materials like green fodder (berseem, lucerne, maize), dry fodder (wheat straw, paddy straw), and silage. These high-fiber feeds provide essential cellulose that maintains rumen function and digestive health while supply
- GeneralClass 12All
Differentiate between capture fishing, aquaculture and mariculture
Capture fishing refers to the traditional practice of harvesting wild fish and other aquatic organisms from their natural habitats—oceans, seas, rivers, and lakes—using various methods like nets, traps, trawlers, and fishing lines. This method relies entirely on naturally occurring fish populations, with fishermen locating and catching fish without any involvement in their breeding or growth. Marine capture fishing targets species like tuna, sardines, mackerel, and prawns in ocean
- GeneralClass 12All
What are the advantages of bee-keeping?
Bee-keeping (apiculture) provides multifaceted economic, agricultural, and environmental benefits with relatively low investment and maintenance requirements. The primary economic advantage is honey production—a high-value natural product with medicinal properties, indefinite shelf life, and strong market demand both domestically and internationally. Beyond honey, bees produce beeswax (used in cosmetics, pharmaceuticals, and candles), propolis (with antimicrobial properties), royal jell
- GeneralClass 12All
What is a layer and a broiler? What are the differences between the two? What are the benefits of poultry farming over cattle farming?
Layers are chicken breeds specifically developed and reared for maximum egg production, typically beginning to lay eggs at 18-20 weeks of age and continuing for 12-14 months of productive laying. Breeds like White Leghorn, Rhode Island Red, and commercial layer hybrids are selected for traits such as high egg output (250-300 eggs per year), efficient feed conversion for egg production, and lighter body weight. Layer farming requires longer rearing periods and specialized nutrition rich in cal
- GeneralClass 12All
What is green manuring? Give example of green manures
Green manuring is the agricultural practice of growing specific fast-growing plants and then ploughing or turning them into the soil while still green (before they flower or set seed) to improve soil fertility and structure. These plants, called green manure crops, are typically legumes or other nitrogen-rich species that are cultivated not for harvest but specifically to be incorporated back into the soil as organic matter. When decomposed, they release essential nutrients—particularly
- GeneralClass 12All
Discuss the preventive measures for the storage of grains
Effective grain storage requires controlling three critical factors: moisture content, temperature, and pest infestation. Before storage, grains must be thoroughly dried to reduce moisture levels below 14% for cereals and 9% for pulses, as higher moisture encourages fungal growth, heating, and rapid quality deterioration. Sun-drying on clean, dry surfaces or using mechanical dryers ensures grains are adequately desiccated. Proper cleaning to remove broken grains, dirt, and foreign matter elim
- GeneralClass 12All
Give difference between manures and fertilizers
Manures are organic materials derived from animal excreta, plant residues, and decomposed organic matter that improve soil fertility by adding humus along with nutrients. Farmyard manure (cow dung mixed with straw), compost, green manure, and vermicompost are common examples that release nutrients slowly as microorganisms break them down. Beyond providing nitrogen, phosphorus, and potassium in modest quantities, manures significantly enhance soil structure, increase water retention capacity,
- GeneralClass 12All
Write a note on cattle feed.
Cattle feed must provide balanced nutrition comprising roughages, concentrates, minerals, and vitamins to maintain health and optimize production. Roughages including green fodder (berseem, lucerne, maize), dry fodder (wheat straw, paddy straw), and silage form 60-70% of a dairy cow's diet, providing fiber essential for rumen function and digestive health. High-producing dairy animals require concentrate mixtures containing energy sources (maize, barley, wheat bran), protein supplements (soyb
- GeneralClass 12All
What is hybridization?
Hybridization is the controlled breeding process where two genetically distinct parent plants or animals are cross-bred to produce offspring (hybrids) with desired traits that combine the best characteristics of both parents. In crop production, scientists and breeders select parent varieties with specific advantageous traits—such as disease resistance, higher yield, drought tolerance, or improved nutritional content—and cross-pollinate them to create hybrid seeds. For instance, h
- GeneralClass 12All
Give difference between Rabi and kharif crop
Kharif crops are sown at the beginning of the monsoon season (June-July) and harvested in September-October, requiring warm, wet conditions for germination and growth. These crops depend heavily on monsoon rainfall and include rice, maize, cotton, soybeans, groundnut, and bajra. The high temperature and humidity during the kharif season suit crops that need substantial water and cannot tolerate frost. Farmers in regions with reliable monsoon patterns prioritize kharif cultivation, as these cr
- GeneralClass 12All
Write a note on culture fisheries.
Culture fisheries involve the scientific rearing of fish in controlled aquatic environments like ponds, tanks, pens, cages, and raceways, where all aspects of production—stocking, feeding, water quality, and harvesting—are managed to maximize yields. This approach differs fundamentally from capture fisheries by controlling fish populations and environmental conditions to achieve production levels of 3,000-6,000 kilograms per hectare annually, compared to unpredictable yields from
- GeneralClass 12All
What are the advantages of organic farming?
Organic farming offers significant environmental and health benefits by eliminating synthetic pesticides and fertilizers, relying instead on natural processes like composting, crop rotation, and biological pest control. This approach improves soil health by increasing microbial activity and organic matter content, which enhances water retention and reduces erosion. The absence of chemical residues makes organic produce safer for consumers, particularly for vulnerable populations like children
- GeneralClass 12All
Differentiate between mixed cropping and inter-cropping
Mixed cropping involves growing two or more crops simultaneously on the same piece of land without any distinct row arrangement, essentially sowing seeds randomly or in a scattered pattern. For example, a farmer might sow wheat, gram, and mustard together in the same field without designated spaces for each crop. This traditional method reduces risk—if one crop fails due to pests or weather, others may still survive—but it makes harvesting, weeding, and applying specific treatment
- GeneralClass 12All
What are the benefits of cattle farming?
Cattle farming delivers year-round economic returns through milk sales, periodic income from selling calves and culled animals, and production of organic manure that reduces fertilizer expenses in integrated farming systems. A well-managed dairy cow produces 10-15 liters of milk daily, creating consistent cash flow when sold through dairy cooperatives or private channels. Indigenous breeds like Gir and Sahiwal, while producing less milk (6-10 liters daily), require lower inputs and show bette
- GeneralClass 12All
Write some preventive measures to control diseases of poultry.
Preventive disease control in poultry begins with comprehensive vaccination programs covering Ranikhet disease (Newcastle disease), Marek's disease, infectious bursal disease (Gumboro), and fowl pox according to scheduled timelines from day-old chicks through production phases. Strict biosecurity protocols include disinfecting footbaths at entry points, restricting visitor access, maintaining separate equipment for different age groups, and implementing all-in-all-out production systems where
- GeneralClass 12All
Write the name of one Indian variety and one exotic variety of bee.
The Indian variety Apis cerana indica (Indian honeybee) is a native species well-adapted to tropical and subtropical climates, while the exotic variety Apis mellifera (Italian bee or European honeybee) has been introduced for commercial honey production. Apis cerana indica is smaller, builds nests in small cavities, and produces 6-8 kilograms of honey per colony annually, making it suitable for traditional beekeeping with minimal investment. This indigenous bee shows superior resistance to lo