शनिवार, 29 जुलाई 2017


(Page No. 204)
1. What do we get from cereals, pulses, fruits and vegetables?

Ans. We get carbohydrates from cereals, proteins from pulses, vitamins and minerals from fruits and vegetables.

(Page No. 205)

1. How do biotic and abiotic factors affect crop production?

Ans. The biotic factors include living organisms like honey bees and earthworms who help in better crop production while pests (insects and rodents) and microbes that produce bad effect on crop production.

The abiotic factors are the climatic conditions and nonliving natural resources like soil, water and air. They also affect crop production since favourable conditions of temperature, humidity and mineral nutrition improve crop production.

2. What are the desirable agronomic characteristics for crop improvements?

Ans. The desirable agronomic characteristics for crop improvements are as follows:

(i) For cereal crops desirable characteristic is dwarfness since such plants will utilise less amount of nutrients.

(ii) For fodder crops desirable characteristics are tallness and profuse branching so that we can obtain more amount of leaves for feeding our animals.

(Page No. 206)

1. What are macro-nutrients and why are they called macronutrients?

Ans. There are sixteen nutrients which are essential for plants. Amongst these thirteen nutrients, six are required in large quantities and are therefore called macronutrients.

Macronutrients: nitrogen, phosphorus, potassium, calcium, magnesium, sulphur.

2. How do plants get nutrients?

Ans. Nutrients are supplied to plants by air, water and soil.



Manure is prepared by the decomposition of animal excreta and plant waste so contains large quantities of organic matter and also supplies small quantities of nutrients to the soil that improves soil fertility.

Fertilizers are commercially produced in factories to supply nitrogen, phosphorus and potassium that ensures soil fertility in terms of proper dose, time, and observing pre and post-application precautions.

(Page No. 207)

1. Compare the use of manure and fertilizers in maintaining soil fertility.


(Page No. 208)

1. Which 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.

Ans. (c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.

(i) The use of good quality seeds increases the total crop production. If a farmer is using good quality seeds, then a majority of the seeds will germinate properly, and will grow into a healthy plant.

(ii) Proper irrigation methods improve the water availability to crops.

(iii) Fertilizers ensure healthy growth and development in plants by providing the essential nutrients such as nitrogen, phosphorus, potassium, etc.

(iv) Crop protection measures include various methods to control weeds, pests, and infectious agents. If all these necessary measures are taken by a farmer, then the overall production of crops will increase.

(Page No. 209)

1. Why should preventive measures and biological control methods be preferred for protecting crops?

Ans. Prevention is better than cure so is true for plants also. Such preventions involve spraying of herbicides, weedicides, insecticides, pesticides, fungicides etc in the crop field.

Since their excessive use can harm the crop plants and cause pollution so proper seed bed preparation, timely sowing of crops, intercropping and crop rotation are additionally applicable. Other than these biological control methods like use of resistant varieties is highly useful.

2. What factors may be responsible for losses of grains during storage?

Ans. Factors that may be responsible for losses of grains during storage are:

·abiotic factors: Unfavourable conditions of humidity and temperature.

biotic factors: Insects, rodents, bacteria, fungi etc that feed on grains.

(Page No. 210)

1. Which method is commonly used for improving cattle breeds and why?

Ans. The method of cross breeding is commonly used for improving cattle breeds for example in milch animals Exotic or foreign breeds (for example, Jersey, Brown Swiss) are selected for long lactation periods, while local breeds (for example, Red Sindhi, Sahiwal) show excellent resistance to diseases. The two can be cross-bred to get animals with both the desired qualities.

(Page No. 211)

1. Discuss 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.”

Ans. Under poultry the birds kept are fed on agricultural waste material and broken grains etc which are not useful for humans but those birds consuming such waste provide us with eggs and meat. It is highly nutritious animal protein food hence the statement made is quite appropriate.

1. What management practices are common in dairy and poultry farming?

Ans. The management practices that are common in dairy and poultry farming are:

·food requirements

·Proper cleaning and shelter facilities

·Protection from unfavorable climatic conditions and diseases.

·Protection from pests.

2. What are the differences between broilers and layers and in their management?


Other than above differences housing, nutritional and environmental requirements of broilers are somewhat different from those of egg layers.

(Page No. 215)

1. How are fish obtained?

Ans. There are two ways of obtaining fish. They can be obtained by:

a) capture fishing: It is the way of obtaining fish from their natural resources (rivers, lakes, oceans).

b) culture fishery: It is also known as fish farming where selected fishes are reared and bred.

2. What are the advantages of composite fish culture?

Ans. Composite fish culture has following advantages:

· Both local and imported fish species can be used in such systems.

· Due to non-competitive nature of selected fishes food available in all the parts of the water reservoir is used.

· Increases the fish yield from the water reservoir (intensive fish farming).

1. What are the desirable characters of bee varieties suitable for honey production?

Ans. The desirable characters of bee varieties suitable for honey production are:

·high honey collection capacity.

·they must sting less.

·They should stay in a given beehive for long periods, and breed very well.

2. What is pasturage and how is it related to honey production?

Ans. Pasturage refers to the flowers available to the bees for nectar and pollen collection. The value or quality of honey depends upon the pasturage. Along with this the kind of flowers available will determine the taste of the honey.

कोई टिप्पणी नहीं:



ईमेल *

संदेश *