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There is more concentration of water in the fruit pieces as compared to the concentration of water in the sugar syrup. Therefore, water is lost out by exosmosis. The membranes of the fruit pieces act as selectively permeable membranes. Thus the process of plasmolysis occurs resulting into shrinking of the fruit pieces.

When green tomatoes become ripe they lose chlorophyll and develop red pigment in them called lycopene. Therefore, ripe tomatoes appear red.

(a) Ribosome – Protein synthesis.

(b) Endoplastic Reticulum – Major site for synthesis of lipid.

(c) Golgi body – Site of formation of glycoproteins and glycolipids.

(d) Nucleolus – Synthesizes the necessary molecules for the production of ribosomes

(e) Cell wall – Gives shape and protects the cells from damage and infection.

In mitochondria, the outer membrane is porous and the inner membrane is deeply folded.

Inorganic inclusions in bacteria are polyphosphate granules (volutin granules) and sulphur granules. These granules are also known as metachromatic granules.

Lysosomes cell organelle is also called “Suicide bag” of cell.

1. Cover slip protects the material under study from coming in contact with the lens of the microscope. 

2. It presses upon the material keeping it plane.

1. The microscope is very useful instrument in the study of cells. 

2. Scientists use electron microscope for their study which can help to see upto a millionth of a meter. 

3. I will appreciate the role of microscope in the growth and development of science and human welfare.

While observing the nucleus of cheek cell in laboratory the following precautions are to be taken.

Precautions: 

1. Do not scrap the cheek too hard as it may injure the buccal mucosa. 

2. Scrapped material should be spread uniformly on the slide. 

3. Excess stains should be drained off. 

4. There should be no air bubbles under the coverslip.

Some Students of the class should name them like mitochondria, endoplasmic reticulum, plastid, vacuole, lysosome, golgi body, etc and tell about them in class; like – 

1. Mitochondria : I am mitochondria. I am covered by a double layer membrane. I am also known as the power house of the cell.

2. Endoplasmic reticulum : I am endoplasmic reticulum. I am also covered by a double layer membrane. I am of two types-Rough endosplasmic reticulum and Smooth endosplasmic reticulum. Ribosomes are attached to my rough endoplasmic reticulum.

3. Plastid : I am plastid. I am present in the cytoplasm of the plant cell. I have many coloured pigments. The greeen pigments are called chloroplast. These give green colour to the leaves. 

4. Lysosome : I am lysosome. I contain very strong digestive enzymes. When the cells get injured or is dead, than I rupture. I am also called suicidal bag.

At a number of places, the nuclear envelope is intercepted by minute pores which are called nuclear pores. These are formed by the fusion of two nuclear membranes. These nuclear pores are the passages through which movement of RNA and protein molecules takes place in both directions between the nucleus and the cytoplasm.