Class 9 Science - Chapter Improvement in Food Resources NCERT Solutions | How do biotic and abiotic factors affect

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?

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?

What is a tissue?

Na⁺ has completely filled K and L shells. Explain.

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?

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

What are the different means by which infectious diseases are spread?

A doctor/nurse/health-worker is exposed to more sick people than others in the community. Find out how she/he avoids getting sick herself/himself.

Does sound follow the same laws of reflection as light does? Explain.

What is osmosis?

Convert into mole.

(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.

Fig 8.11 shows the distance-time graph of three objects A,B and C. Study the graph and answer the following questions:

          Fig. 8.11

(a) Which of the three is travelling the fastest?
(b) Are all three ever at the same point on the road?
(c) How far has C travelled when B passes A?
(d) How far has B travelled by the time it passes C?