NCERT books offer a number of problems which students can practice to assess their learning and prepare for the examinations. Practicing a variety of questions helps to strengthen the fundamentals of a topic which makes students efficient in solving different questions asked in exams based on that particular topic. Therefore, students are suggested to solve all the NCERT questions and learn to write perfect solutions which will help them score good marks in exams.
For all the questions given in CBSE Class 9 Science NCERT book we have collated detailed and accurate answers that will help students find the right approach to solve different questions.
Here, we are providing the NCERT solutions for Class 9 Science chapter 15, Improvement in Food Resources. Our subject experts have reviewed these NCERT solutions to provide you the error free content which will make it easy for you to make an effective preparation for the annual exams.
Main topics discussed in Class 9 Science chapter- Improvement in Food Resources are:
Students may download all the NCERT Solutions for CBSE Class 9 Science chapter – Improvement in Food Resources, in the form of PDF.
Some of the questions and their solutions from NCERT Solutions for Class 9: Improvement in Food Resources, are as follows:
Q. What do we get from cereals, pulses, fruits and vegetables?
The things we get from cereals, pulses, fruits and vegetables are as follows:
Cereals (wheat, rice, maize, etc.): are the sources of carbohydrates which provide energy.
Pulses (pea, gram and soybean, etc.): are source of proteins.
Vegetables and fruits: provide us vitamins, minerals, carbohydrates, proteins and fats.
Q. What are the macronutrients and why are they called macronutrients?
Macronutrients are essential elements which are required by plants in major quantities. Some of the main macronutrients are:
(i) N, P, S which are found in proteins.
(ii) Ca is found in cell wall.
(iii) Mg is a part of chlorophyll.
Q. Compare the use of manure and fertilisers in maintaining soil fertility.
Use of manure in maintaining soil quality:
(i) Manures are the very rich source of organic matter (humus) for the soil. Humus helps to restore water retention capacity of sandy soil and drainage in clayey soil.
(ii) Manures are the sources of soil organisms like soil friendly bacteria.
Effects of fertilisers on soil quality:
(i) Excess use of fertilisers cause to dryness of soil and hence the rate of soil erosion increases.
(ii) Continuous use of fertilisers decreases the organic matter which reduces the porosity of the soil and the plant roots do not get sufficient oxygen.
Q. What factors may be responsible for the losses of grains during storage?
Following are the factors responsible for loss of grains during storage:
(i) Abiotic factors like humidity and temperature.
(ii) Biotic factors like insects, rodents, birds, mites and bacteria.
Q. Explain anyone method of crop production which ensures high yield.
Inter cropping is a method used for a high yielding crop production. In this method, two or more crops are grown simultaneously on the same field in definite pattern. A few rows of one crop alternate with a few rows of second crop.
Example: soybean, maize or finger millet (bajara) and caw pea (labia).
The selected crops should have different nutrient requirements. This ensures maximum utilisatian of the nutrients supplied. It also prevents pests and diseases from spreading to all the plants belonging to one crop in a field. This method gives a better crop yield.
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