How is a prokaryotic cell different from a eukaryotic cell?
Prokaryotic cell is by and large more modest in size (1-10 pm), atomic region is ineffectively characterized, the cell organelles are not membrane bound and has a single chromosome.
Eukaryotic cells are for the most part bigger in size (5-100 pm), atomic locale is obvious with atomic membrane. Membrane bound cell organelles are available and have more than one chromosome.
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.
Prokaryotic Cell | Eukaryotic Cell |
1. Size : generally small (1-10 μm) 1 μm = 10-6 m |
1. Size generally large (5-100 μm) |
2. Nuclear region: ________________ and known as _________________ |
2. Nuclear region: well defined andsurrounded by a nuclear membrane |
3. Chromosome: single |
3. More than one chromosome |
4. Membrane-bound cell organelles absent | 4. _______________________ _______________________ |
Why is the cell called the structural and functional unit of life?
Why are lysosomes known as suicide bags?
Where do the lipids and proteins constituting the cell membrane get synthesised?
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?
Which organisms are called primitive and how are they different from the so-called advanced organisms?
Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.
Why does an object float or sink when placed on the surface of water?
What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?
What is the importance of universal law of gravitation?
What is genetic manipulation? How is it useful in agricultural practices?
What is meant by the term chemical formula?
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?
A certain household has consumed 250 units of energy during a month. How much energy is this in joules?