Class 9 Science - Chapter The Fundamental Unit of Life NCERT Solutions | Where do the lipids and proteins constit

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.

How does an Amoeba obtain its food?

Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.

Why is the cell called the structural and functional unit of life?

Why are lysosomes known as suicide bags?

How is a prokaryotic cell different from a eukaryotic cell?

Make a comparison and write down ways in which plant cells are different from animal cells.

How do substances like CO2 and water move in and out of the cell? Discuss.

Where are proteins synthesised inside the cell?

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

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?

Convert into mole.

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

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?

In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?

Certain force acting on a 20 kg mass changes its velocity from 5 m s^-1 to 2 m s^-1. Calculate the work done by the force.

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

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

Calculate the molecular masses of H₂, O₂, Cl₂, CO₂, CH₄, C₂H₆, C₂H₄, NH₃, CH₃OH.

A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.

What is the mass of—

(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?
(c) 10 moles of sodium sulphite (Na₂SO₃)?

What precautions can you take in your school to reduce the incidence of infectious diseases?