Class 9 Science Improvement in Food Resources: NCERT Solutions for Question 1

How do you differentiate between capture fishing, mariculture and aquaculture?

Explain any one method of crop production which ensures high yield.

How do good animal husbandry practices benefit farmers?

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

How do plants get nutrients?

How are fish obtained?

What are the desirable agronomic characteristics for crop improvements?

What is genetic manipulation? How is it useful in agricultural practices?

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

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

Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?

State the universal law of gravitation.

Which of the following are matter?

Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.

A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?

What is meant by a pure substance?

How does the sound produced by a vibrating object in a medium reach your ear?

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.

sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water

What are canal rays?

State any two conditions essential for good health.

How is our atmosphere different from the atmospheres on Venus and Mars?

Explain how the human ear works.

What is power?

Do you know of any activity which may be polluting this water source?

A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate:

(a) the net accelerating force;
(b) the acceleration of the train; and
(c) the force of wagon 1 on wagon 2.

Why do organisms need water?

Which wave property determines
(a) loudness,    (b) pitch?

How are clouds formed?

A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m s^-2 for 8.0 s. How far does the boat travel during this time?

What causes winds?

Isotopes of an element have

(a) the same physical properties
(b) different chemical properties
(c) different number of neutrons
(d) different atomic numbers.