Class 9 Science - Chapter Improvement in Food Resources NCERT Solutions | What factors may be responsible for loss

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

How do good animal husbandry practices benefit farmers?

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

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

How do plants get nutrients?

How are fish obtained?

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

What are the desirable agronomic characteristics for crop improvements?

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

How do biotic and abiotic factors affect crop production?

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?

Identify the type of tissue in the following: skin, bark of tree, bone, lining of kidney tubule, vascular bundle.

Write down the names of following formulae:

(i) Al₂(SO₄)₃
(ii) CaCl₂
(iii) K₂SO₄
(iv) KNO₃
(v) CaCO₃.

We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?

What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

How does an Amoeba obtain its food?

A large truck and a car, both moving with a velocity of magnitude v, have a head-on collision and both of them come to a halt after that. If the collision lasts for 1 s:
(a) Which vehicle experiences the greater force of impact?
(b) Which vehicle experiences the greater change in momentum?
(c) Which vehicle experiences the greater acceleration?
(d) Why is the car likely to suffer more damage than the truck?

What would happen to the life of a cell if there was no Golgi apparatus?

Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.

Number of valence electrons in Cl^-ion are:
(a) 16          (b) 8          (c) 17          (d) 18

Explain the following giving examples.

(a) saturated solution
(b) pure substance
(c) colloid
(d) suspension