CBSE – 8th Standard Science

Chapter 8

Cell structure and functions

 

Q1. What is a cell made up of?

Ans. The cell has three main parts, the cell membrane, cytoplasm, small organelles and nucleus.

 

Q2. Which part of the cell contains organelles?

Ans. Organelles, of cells are present in the the jelly-like substance between the nucleus and the cell membrane cytoplasm.

 

Q3. State the difference between eukaryotes and prokaryotes.

Ans. The cells having nuclear material without nuclear membrane are termed prokaryotic cells.

The cells, having well organized nucleus with a nuclear membrane are eukaryotic cells.

 

Q4. Where are chromosomes found in a cell? State their function.

Ans. Nucleus contains thread-like structures called chromosomes. These carry genes and help in inheritance or transfer of characters from the parents to the offspring.

 

Q5. Which part controls the activity in cell?

Ans. Nucleus, in addition to its role in inheritance, acts as control centre of the activities of the cell

 

Q6. ‘Cells are the basic structural units of living organisms’. Explain

Ans. The single cell of organisms performs all the basic functions performed by a variety of cells in multicellular organisms like taking food, digest and reproduction thus it’s a basic unit of life.

 

 

Q7. Explain why chloroplasts are found only in plant cells?

Ans. . Plants make their food own, green plastids containing chlorophyll are called chloroplasts, they are found in plants because it captures sunlight for photosynthesis.

 

 

Q8. Are the cells in an elephant larger than the cells in a rat?

Ans. The size of the cells has no relation with the size of the body of the animal or plant.

 

Q9. Is transport between cells possible?

Ans. The cells membrane is porous and allows the movement of substances or materials both inward and outward.

 

Q10. Which part of the cell gives it shape?

Ans. Components of the cell are enclosed in a membrane. This membrane provides shape to the cells of plants and animals.

 

Q11. What is the different in a plant cell?

Ans.  Cell wall is an additional covering over the cell membrane in plant cells. It gives shape and rigidity to these cells, Vacuoles are large than the animal cell.

 

 

Try these :-

 

What is the need of staining the cells? Name any four stains.

 

Define a vacuole inside a cell and mention its importance?

 

How is a cell wall different from plasma membrane?

 

List the different functions performed by cell membrane.

 

What are the main postulates of the cell theory?