1What do we get from cereals, pulses, fruits and vegetables?
Answer & Reference:
Cereals provide carbohydrates for energy. Pulses provide proteins. Fruits and vegetables provide vitamins and minerals along with small amounts of proteins, carbohydrates and fats. (Page 141, Para 1)
2How do biotic and abiotic factors affect crop production?
Answer & Reference:
Biotic factors (diseases, insects, nematodes) and abiotic factors (drought, salinity, water logging, heat, cold, frost) can reduce crop production by damaging plants and affecting their growth. (Page 142, Para 2)
3What are the desirable agronomic characteristics for crop improvements?
Answer & Reference:
For fodder crops, tallness and profuse branching are desirable. For cereals, dwarfness is desired so that less nutrients are consumed by the crops. (Page 142, Para 2)
4What are macro-nutrients and why are they called macro-nutrients?
Answer & Reference:
Macro-nutrients are nutrients required by plants in large quantities. They include nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur. They are called macro-nutrients because plants need them in large amounts. (Page 143, Table 12.1)
5How do plants get nutrients?
Answer & Reference:
Plants get nutrients from air (carbon, oxygen), water (hydrogen, oxygen), and soil (thirteen other nutrients including macro and micro-nutrients). (Page 143, Table 12.1)
6Compare the use of manure and fertilizers in maintaining soil fertility.
Answer & Reference:
Manure enriches soil with nutrients and organic matter, improves soil structure, and increases water holding capacity. Fertilizers supply specific nutrients (N, P, K) but continuous use can destroy soil fertility by harming micro-organisms and not replenishing organic matter. (Page 143, Para 2-3)
7Which of the following conditions will give the most benefits? Why? (a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers. (b) Farmers use ordinary seeds, adopt irrigation and use fertilizer. (c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
Answer & Reference:
Option (c) will give the most benefits because it combines all essential practices: quality seeds ensure good yield potential, irrigation provides necessary water, fertilizers supply nutrients, and crop protection measures prevent losses from pests and diseases. (Page 145, Question)
8Why should preventive measures and biological control methods be preferred for protecting crops?
Answer & Reference:
Preventive measures and biological control methods are preferred because excessive use of chemical pesticides causes environmental pollution and can be poisonous to many plant and animal species. Biological methods are eco-friendly. (Page 146, Question 1)
9What factors may be responsible for losses of grains during storage?
Answer & Reference:
Biotic factors: insects, rodents, fungi, mites, bacteria.
Abiotic factors: inappropriate moisture and temperatures in storage.
These cause degradation in quality, weight loss, poor germinability, and discolouration. (Page 146, Question 2)
10Which method is commonly used for improving cattle breeds and why?
Answer & Reference:
Cross-breeding between local breeds (like Red Sindhi, Sahiwal) and exotic breeds (like Jersey, Brown Swiss) is commonly used. This combines disease resistance of local breeds with long lactation periods of exotic breeds. (Page 147, Question)
11What management practices are common in dairy and poultry farming?
Answer & Reference:
Common practices include proper shelter with ventilation, regular cleaning, balanced nutrition, disease prevention through vaccination, and maintaining hygienic conditions. (Page 148, Question 1)
12What are the differences between broilers and layers and in their management?
Answer & Reference:
Broilers are raised for meat and require protein-rich feed with high vitamins A and K. Layers are raised for egg production and require proper lighting and space. Housing, nutritional, and environmental requirements differ between them. (Page 148, Question 2)
13Discuss the implications of the following statement: "It is interesting to note that poultry is India's most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food."
Answer & Reference:
This statement implies that poultry efficiently converts agricultural by-products and low-quality grains (unsuitable for humans) into high-quality protein in the form of eggs and meat, making it an economical and sustainable source of nutrition. (Page 148, Question)
14How are fish obtained?
Answer & Reference:
Fish are obtained through two methods: (1) Capture fishing from natural resources (marine and inland), and (2) Culture fishery (fish farming) in marine and freshwater ecosystems. (Page 150, Question 1)
15What are the advantages of composite fish culture?
Answer & Reference:
Composite fish culture uses 5-6 fish species with different feeding habits (surface, middle-zone, bottom feeders) in the same pond. This ensures complete utilization of available food without competition, increasing fish yield. (Page 150, Question 2)
16What are the desirable characters of bee varieties suitable for honey production?
Answer & Reference:
Desirable characters include: high honey collection capacity, less stinging, staying in the beehive for long periods, and good breeding capacity. The Italian bee (A. mellifera) has these qualities. (Page 150, Question 1)
17What is pasturage and how is it related to honey production?
Answer & Reference:
Pasturage refers to the flowers available to bees for nectar and pollen collection. It determines both the quantity and quality (taste) of honey produced. (Page 150, Question 2)
18Explain any one method of crop production which ensures high yield.
Answer & Reference:
Crop variety improvement ensures high yield by developing varieties with higher yield potential, improved quality, resistance to biotic/abiotic stresses, shorter maturity duration, wider adaptability, and desirable agronomic characteristics. (Page 151, What you have learnt)
19Why are manure and fertilizers used in fields?
Answer & Reference:
Manure and fertilizers are used to supply essential nutrients to crops. Manure enriches soil with organic matter and nutrients, while fertilizers provide specific nutrients like nitrogen, phosphorus, and potassium to ensure healthy plant growth and high yields. (Page 143, Para 1; Page 151)
20What are the advantages of inter-cropping and crop rotation?
Answer & Reference: Inter-cropping: Ensures maximum nutrient utilization, prevents pest/disease spread, and gives better returns. Crop rotation: Maintains soil fertility, reduces pest buildup, and allows multiple crops per year. (Page 145, Para 1-2; Page 151)
21What is genetic manipulation? How is it useful in agricultural practices?
Answer & Reference:
Genetic manipulation involves introducing a gene for a desired characteristic into a crop, resulting in genetically modified crops. It's useful for developing varieties with higher yield, better quality, stress resistance, and shorter maturity duration. (Page 141, Para 2; Page 151)
22How do storage grain losses occur?
Answer & Reference:
Storage losses occur due to:
- Biotic factors: Insects, rodents, fungi, mites, bacteria
- Abiotic factors: Inappropriate moisture and temperature
These cause quality degradation, weight loss, poor germinability, and discolouration. (Page 146, Para 1)
23How do good animal husbandry practices benefit farmers?
Answer & Reference:
Cattle farming provides:
- Milk from milch animals
- Draught labor for agricultural work (tilling, irrigation, carting)
- Additional income through dairy products (Page 146, Para 2; Page 151)
25For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer & Reference:
Common practices for increasing production include:
- Cross-breeding/improved varieties
- Proper nutrition and feeding
- Disease prevention and control
- Scientific management practices (Page 147-150; Page 151)
26How do you differentiate between capture fishing, mariculture and aquaculture?
Answer & Reference:
- Capture fishing: Obtaining fish from natural resources (marine and inland)
- Mariculture: Culture of marine organisms (fish, prawns, oysters) in seawater
- Aquaculture: Farming of aquatic organisms (fish, prawns) in freshwater or brackish water (Page 148-149; Page 151)
27Provide the nutritional values of animal products as given in Table 12.2.
Answer & Reference:
Animal Products
Fat (%)
Protein (%)
Sugar (%)
Minerals (%)
Water (%)
Vitamins
Milk (Cow)
3.60
4.00
4.50
0.70
87.20
B1, B2, B12, D, E
Egg
12.00
13.00
*
1.00
74.00
B2, D
Meat
3.60
21.10
*
1.10
74.20
B2, B12
Fish
2.50
19.00
*
1.30
77.20
Niacin, D, A
*Present in very small amounts (Page 146, Table 12.2)
28List the nutrients supplied by air, water, and soil to plants as per Table 12.1.