What will happen if an animal or plant cell is put into a solution of sugar and water?

2

(a)

Who discovered cells and how?

2

(a)

Difference between diffusion and osmosis. Write any two examples where a living organism uses osmosis to absorb water.

2

(a)

Distinguish between hypotonic solution, isotonic solution and hypertonic solution.

2

(a)

What is the significance of cell wall in plant cell?

2

(a)

Distinguish between plasma membrane and cell wall.

2

(a)

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

Prokaryotic Cell	Eukaryotic Cell
Size: generally small (1-10 μm)	Size: generally large (5-100μm)
Nuclear region:..............................................................and known as.................................................	Nuclear region: well-defined and surrounded by a nuclear membrane.
Chromosome: Single	More than one chromosome.
Membrane-bound cell organelles absent.	...........................................................

2

(a)

What is cytoplasm?

2

(a)

What is the function of an endoplasmic reticulum?

2

(a)

What are lysosomes?

2

(a)

(a) Name the organelle which provides turgidity and rigidity to the plant cell. Name any two substances which are present in it.
(b) How are they useful in unicellular organisms?

2

(a)

Write functions of the
(i) Inner membrane of mitochondria.
(ii) Nucleus of the cell.
(iii) Ribosomes present in active cells.

2

(a)

Which organelle is known as the powerhouse of the cell? Why?

2

(a)

The nail lies on a nail bed. The proximal part of the nail lies in the nail groove of the skin and the white part at called the lunula, is the portion from which the nail grows forward. The nail is firmly attached with the nail bed. The distal extremity of the nail is free-the free border. As the nail grows, the free border increases in length. This portion is formed of dead cells, which contain a tough substance called keratin. The dirt, dead cells of skin and other substances, such as bacteria due to itching or handling substances get deposited under the long grown nails.
On the basis of above information answer the following questions:
(i) What harm long nails can do to us?
(ii) What should we do to prevent this?
(iii) How would you use your knowledge regarding nails in the benefit of society?

2

(a)

Differentiate between diffusion and Osmosis.

2

(a)