Class 9 Science Chapter 12 Question Answers - Improvement in Food Resources

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Q1: Name any two fodder crops.
Ans: Berseem and Sudan grass are raised as food for the livestock, called fodder crops.

Q2: What do you understand by photoperiod of sunlight?
Ans: Photoperiods are related to the duration of sunlight required for plant growth.

Q3: Name two kharif crops.
Ans: Paddy and soybean.

Q4: Name two rabi crops.
Ans: Wheat and gram.

Q5: Define hybridization.
Ans: Hybridization refers to crossing between genetically dissimilar plants to obtain a better variety of crops.

Q6: What are genetically modified crops?
Ans: A gene with required characters can be introduced into a crop for its improvement; this crop is called genetically modified crop.

Q7: “Shorter the duration of the crop from sowing to harvesting, the more economical is the variety.” Give reason for this.
Ans: Farmers can grow more crops in a year due to short duration of crop growth and reduce the cost of crop production.

Q8: Name different types of crop production practices involved in India.
Ans: They are (a) no cost production, (b) low cost production and (c) high cost production.

Q9: What is mariculture?
Ans: The culture of marine fish in sea water is called mariculture.

Q10: What are macro-nutrients?
Ans: The nutrients required by plants in larger quantity are called macro-nutrients. They are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Q11: Name the nutrients that plant obtains from air and water.
Ans: Air - Carbon and oxygen, Water - Hydrogen and oxygen.

Q12: State the difference between compost and vermicompost.
Ans: Compost is obtained by decomposition of organic waste naturally due to decomposition by bacteria. Vermi-compost is obtained by adding red-worms to organic matter to speed up decomposition.

Q13: What is a wave?
Ans: A wave is a disturbance that travels in a medium due to repeated periodic motion of particles about their mean position – such that the disturbance is handed over from one particle to the other without the actual motion of the medium.

Q14: How does deficiency of nutrients affect the crop?
Ans: Physiological processes can be affected by deficiency of any nutrient in plants including reproduction, growth and susceptibility to diseases.

Q15: Name the two types of mechanical waves.
Ans: They are
(i) Transverse wave and
(ii) Longitudinal wave.

Q16: What is sound and how is it produced?
Ans: Sound is mechanical energy which produces a sensation of hearing. When an object is set into vibrations, sound is produced.

Q17: What is a trough?
Ans: A trough is a depression in a wave, i.e., maximum displacement in the negative direction (below the mean position).

Q18: Name two Indian cattle.
Ans: Bos indicus - cows, Bos bubalis - buffaloes.

Q19: How does Bos indicus differ from Bos bubalis?
Ans: Bos indicus is a cow while Bos bubalis is a buffalo.

Q20: Name the two vitamins which are added in the poultry feed.
Ans: Vitamins A and K.

Q21: From where do plants acquire the following nutrients?
(a) Nitrogen,
(b) Hydrogen.
Ans:
(a) Nitrogen from soil,
(b) Hydrogen from water.

Q22: What do you understand by the term echo?
Ans: The sound heard after reflection from a rigid obstacle is called an echo.

Q23: What is animal husbandry?
Ans: Animal husbandry is the management and care of farm animals by humans for profit.

Q24: Mention the components of food present in vegetables and fruits.
Ans: Vegetables, spices and fruits provide a range of vitamins and minerals in addition to small amounts of proteins, carbohydrates and fats.

Q25: What causes disease in plants?
Ans: It is caused by pathogens such as bacteria, fungi and viruses.