Class 9 Science - Chapter Diversity in Living Organisms NCERT Solutions | What are the advantages of classifying o

How do poriferan animals differ from coelenterate animals?

Explain the basis for grouping organisms into five kingdoms.

Explain how animals in Vertebrata are classified into further subgroups.

Which organisms are called primitive and how are they different from the so-called advanced organisms?

How do gymnosperms and Angiosperms differ from each other?

Give three examples of the range of variations that you see in life-forms around you.

What are the major divisions in the Plantae? What is the basis for these divisions?

How do annelid animals differ from arthropods?

Which do you think is a more basic characteristic for classifying organisms?

(a) the place where they live.
(b) the kind of cells they are made of. Why?

What are the differences between amphibians and reptiles?

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?

Carry out the following osmosis experiment:

Take four peeled potato halves and scoos each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,

(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.

Keep these for two hours. Then observe the four potato cups and answer the following:

(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D.

The volume of a 500 g sealed packet is 350 cm³. Will the packet float or sink in water if the density of water is 1 g cm^-3? What will be the mass of the water displaced by this packet?

What is the major source of fresh water in the city/town/village where you live?

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

An electric heater is rated 1500 W. How much energy does it use in 10 hours?

Define average power.

What is soil erosion?

Name the regions in which parenchyma tissue is present.

What are the methods of preventing or reducing soil erosion?

Which characteristic of the sound helps you to identify your friend by his voice while sitting with others in a dark room?