The Cell and Its Structure and Functions

The Cell and Its structure and Functions

1. Name the person who first coined the term “Cell”        Ans: Robert Hooke in 1665, first coined the term Cell.

2. Define Cell        Ans: Cell is defined as the basic structural and functional unit of living organisms.

3. What will happen to a cell if its nucleus is removed?        Ans: With the passage of time, the cell will die as the nucleus which controls and coordinates all the functions of the cell is absent.

4. Give 5 examples of single celled organisms.        Ans: Paramecium, Amoeba, Chlamydomonas, Bacteria, Malarial Parasite

5. What are multicellular organisms ? Give an example.        Ans: The organisms consisting of more than one (multiple) cells, where each cell performs a specialized function is known as Multicellular Organism. Example:- Animals, Plants, Fungi

6. The cell organelle which is commonly referred as the suicidal bags of the cell.        Ans: Lysosomes.

7. Name the process through which an amoeba acquires its food from the external surroundings.        Ans: The process through which an amoeba acquires its food from the external environment is called Endocytosis.

8. State the functions of chromosome in a cell.        Ans: Chromosome is the carrier of genetic information.

9. Who proposed the Cell theory ?        Ans: Schielden and Schwann proposed the cell theory (i.e. all organisms have cell and cell is the basic unit of life), it was further expanded by Virchow (by suggesting that all cells arise from pre-existing cells).

10. What is Nucleoid ?        Ans: The undefined nuclear region of Prokaryotic cell (Bacteria, Blue Green Algae) is known as Nucleoid.

11. Define diffusion.        Ans: Diffusion is defined as the movement of particles from a region of High Concentration to a region of low concentration.

12. Plasma membrane is formed of?        Ans: Plasma Membrane is formed of Proteins and Lipids.

13. Identifiy and name the following cell structures: 

 a) The undefined nuclear region of Prokaryotic cell.        

 b) Site of energy release inside the cell.        Ans: a) Nucleoid b) Mitochondria

14. Name the kind of plastid which is important for photosynthesis in leaves of the plants.        Ans: Chloroplast.

15. Name the two components of chromosomes.        Ans: Proteins and DNA.

16. When does the chromatin network separate out to form chromosomes?        Ans: The network of Chromatin fibres separate out to form chromosomes, when a cell is at dividing stage (dividing/about to divide).