Free download NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources in PDF format. Class 9 Science Solutions of all chapters are given at one place. NCERT Solutions for class 9 all subjects are also available.
NCERT Solutions for Class 9 Science Chapter 15
Class 9 Science – Biology – Improvement in Food Resources
Important Questions with Answers
- Question 1:
Explain any one method of crop production which ensures high yield.
- Answer 1:
Hybridisation helps to increase the crop production. It involves crossing of inter-variety, inter-specific crossing, inter-generic crossing which give plants of desired characteristics, i.e., high yield of crops which are disease resistant and respond to fertilisers positively, adaptable to the environment, need less water for irrigation and have low maturity periods.
- Question 2:
If there is low rainfall in a village throughout the year, what measures will you suggest to the farmers for better cropping?
- Answer 2:
(i) Use nearby rivers directly, if available .
(ii) Use canals if available and river lift system if flow of water is slow.
(iii) Use tube wells, if possible.
(iv) Use tanks and pounds which can store rain-water.
(v) Reduce tilting. Enrich the soil with humus.
(vi) Use of drought resistant variety of corps.
- Question 3:
Why should preventive measures and biological control method be preferred for protecting crops?
- Answer 3:
Resistant crops variety are useful and give higher yield. Biological control methods are safe, ecofriendly, long lasting and harmless to other forms of life, therefore should be preferred.
- Question 4:
Why are manure and fertilizers used in fields?
- Answer 4:
Manure and fertilizers supply nutrients to the soil and increases the fertility of the soil and thus increases the production. They overcome the nutritional deficiency of the soil.
- Question 5:
What are macro nutrients and why they are called macro nutrients?
- Answer 5:
Those nutrients which are required by plants in large amount are called macro-nutrients. Nitrogen, Potassium, Phosphorus, Calcium, Magnesium and Sulphur are macro nutrients.
They are required by the plants in large amounts to carry out the various life processes and that is why, they are called macronutrients.
- Question 6:
What is genetic manipulation? How is it useful in agricultural practices?
- Answer 6:
The process refers to the transfer of genes from one organism to another, e.g. Bt Cotton is a genetically modified crop which carry bacterial genes, that protects this plant from insects. These are used in rice, maize, brinjal, cabbage, cauliflower to get protection from insects.
- Question 7:
What are the advantages of inter-cropping and crop-rotation?
- Answer 7:
(i) Prevents pests and decreases the chances of spoiling of whole crops, therefore reduce losses and both crops can give better results.
(ii) It can also deal with less monsoon or drought because crop which needs less water can easily survive.
(i) Farmers can grow two or three crops in a year.
(ii) Pulses take nitrogen directly from the atmosphere, and thus needed fewer amounts of fertilisers.
(iii) Vegetables and fruits can be easily grown. It makes best use of land and nutrients present in the soil.
- Question 8:
Give the merits and demerits of fish culture?
- Answer 8:
(i) We get economically desired fish.
(ii) Fishes are made to breed in different seasons by hormonal stimulation.
(iii) There is less mortality.
(iv) Though hybridisation or cross breeding high yield and quality of fishes can be obtained.
(v) A large number of fishes can be raised in small area.
(i) It give rise to monoculture.
(ii) Biodiversity may be threatened by it.
(iii) Some varieties of fishes may get extinct.
- Question 9:
What are the benefits of cattle farming?
- Answer 9:
(i) Milk production is increased by special animal breed obtained through cross breeding.
(ii) Good quality of meat can be obtained.
(iii) Good breed of draught animals can be produced.
(iv) The plant materials/crops-wastes/ weeds/ fodder corps from the field can be used.
(v) Excretion of animals can be changed into bio-gas and manure.
- Question 10:
What is pasturage and how is it related to honey production?
- Answer 10:
Pasturage is the availability of flowers for nectar and pollen collection for honeybee.
The kind and quality of honey is determined by the kind and quality of pasturage.
- Question 11:
What are the differences between broilers and layers and in their management?
- Answer 11:
(i) They are maintained for getting meat.
(ii) They are raised up to 6-7 weeks.
(iii) They need less space and in this condition they grow fast and have low morality.
(iv) They need food rich in proteins, adequate fat along with vitamin A and K.
(i) They are needed for eggs.
(ii) They start laying egg after 20 weeks.
(iii) They need enough space, suitable temperature and high morality.
(iv) They need restricted food with vitamins, minerals and micro-nutrients.