3. A cell is defined as the basic structural and functional unit of an organism.

4. Cell membrane nucleus centrosomes ribosome Smooth ER Rough er golgi mitochondrion lysosomes vacuole

5. THE INTRA CELLULAR STRUCTURES FOUND SUSPENDED IN THE CYTOPLASM ARE CALLED CELL ORGANELLES.

7. In the animal cell the nucleus is in the center. It consists of four parts,they are:- Nuclear membrane. Nucleoplasm. Nucleolus and chromatin. Function : - nucleus controls the activities of the cell. They contain hereditary characteristics to be passed on to the next generation.

8. Centrosomes are also called as centrioles. Function:-they help in cell division.

9. Ribosomes contain protein and RNA (ribose nucleic acid) Function:-they form the site for protein synthesis.

10. These are the chemical components which do not have definite structures and are grouped together in the cytoplasm of the cell.

12. There are two types of endoplasmic reticulum. They are:- Rough endoplasmic reticulum. Smooth endoplasmic reticulum. Function:- It forms the supporting skeleton network of the cell. It forms the site for reactions of the cell.

13. Function:-They are secretary in function. The synthesized products of the cell are collected by them and secreted into the cytoplasm

14. Mitochondria are also called as power house of the cell. Function:-they form the site for cellular respiration. They oxidize the carbohydrates to release energy,a portion of which is used to form atp (adenosine tri phosphate) molecules.

15. Function:-The enzymes present in lysosomes can digest worn out cell or Unwanted materials of the cell.

16. In animal cell there may be small vacuole or even absent. It is covered by tonoplast. Function:-It helps in storage of food, water and waste.