Class 9 Science
Question 1: What do we get from cereals, pulses, fruits and vegetables?
Answer: We get carbohydrate from cereals, proteins from pulses and vitamins and minerals from fruits and vegetables.
Question 2: How do biotic and abiotic factors affect crop production?
Answer: Crop production can go down due to biotic and abiotic factors under different situations.
Question 3: What are the desirable agronomic characteristics for crop improvements?
Answer: Desirable agronomic characteristics vary from one crop to another. For example; fodder crops need to be tall and should have profuse branching. Cereal crops should be dwarf so that less amount nutrients can be consumed by the plant and more nutrients can be channelized to making grains.
Question 4: What are macro-nutrients and why are they called macronutrients?
Answer: Nutrients which are required in large quantity are called macronutrients. Examples: nitrogen, phosphorus,potassium, calcium, magnesium, sulphur.
Question 5: How do plants get nutrients?
Answer: Plants get most of the nutrients from soil. They get carbon and oxygen from air, and get hydrogen and oxygen from water.
Question 6: Compare the use of manure and fertilizers in maintaining soil fertility.
|Manure improves soil structure.||Fertilizer has no effect on soil structure.|
|Manure provides small amount of plant nutrients.||Fertilizer provides plenty of plant nutrients.|
|Manure is slow to act.||Fertilizer is fast to act.|
|Manure gives long term benefits.||Fertilizer gives short term benefits.|
Question 7: Which of the following conditions will give the most benefits? Why?
Answer: The most beneficial condition is (c), i.e. farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures. High quality seeds will produce better plants when crop is well irrigated, is supplied with suitable nutrients and is protected against weeds and pests.
Question 8: Why should preventive measures and biological control methods be preferred for protecting crops?
Answer: Using chemicals for protecting the plants against weeds and pests has many side effects. These chemicals are detrimental to the environment and food chain. Some of these chemicals can be poisonous as well. But preventive measures and biological control are safe and environment-friendly. Hence, these methods should be preferred for protecting crops.
Question 9: What factors may be responsible for losses of grains during storage?
Answer: Moisture, non-conducive temperature, fungi, pests, etc.
Question 10: Which method is commonly used for improving cattle breeds and why?
Answer: Hybridization helps in incorporating desirable characters in cattle. Hence, this method is commonly used for improving cattle breeds.
Question 11: What management practices are common in dairy and poultry farming?
Answer: Following management practices are common in dairy and poultry farming:
Question 12: What are the differences between broilers and layers and in their management?
Answer: Broilers need a ration which is rich in protein with adequate amount of fat. Layers need a ration which is rich in calcium. Other practices; for food and shelter are same for both varieties.
Question 13: 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.”
Answer: Poultry feed is prepared from corn, soya, and many farm waste. Most of the ingredients in poultry feed is unfit for human consumption. But these materials are properly utilized by poultry. The poultry; in turn; converts these materials into meat and eggs. Thus, low fibre food stuff is converted into highly nutritious protein-rich food for humans. This has resulted in better availability of eggs and chicken all over the country. It has ensured more people now have access to meat and meat products.
Question 14: How are fish obtained?
Answer: Fish are obtained by two methods:
Capture Fishing: When fish is captured from natural reservoirs, it is called capture fishing.
Fish Farming: When fish is artificially bred and raised in water reservoirs, it is called fish farming.
Question 15: What are the advantages of composite fish culture?
Answer: Composite fish culture helps in better utilization of food available in a pond or lake. It also helps in ensuring maximum fish production in a reservoir.
Question 16: What are the desirable characters of bee varieties suitable for honey production?
Answer: Increased production of honey, less chances of stinging
Question 17: What is pasturage and how is it related to honey production?
Answer: An orchard full of flowers or a forest or a farmland from where the honey bees collect nectar and pollen grains is called pasturage. Quality of honey depends on the pasturage. Taste of honey depends on the type of flower.
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