Question

Write the main function of:

1. Cell wall
   
2. Cell membrane
   
3. Endoplasmic reticulum
   
4. Mitochondria
   
5. Plastids
   
6. Ribosome
7. Golgi body
8. Lysosome
9. Centrosome
10. Vacuoles
11. Nucleus
12. Chromosome
    

Answer 1

Cell- A cell is considered to be the basic structural and functional unit of life and is composed of various parts and organelles within them.

1. Cell wall- It is seen among microbes and plant cells and is a rigid structure made up of cellulose in plants and peptidoglycan in bacteria. It protects the cells from external injury.
   
2. Cell membrane- The cell membrane separates the cell contents from its surroundings. The cell membrane controls the movement of substances in and out of cells.
3. Endoplasmic reticulum (ER)- It is involved in the process of modification and synthesis of new proteins and routing them. It remains closely attached to the nucleus and has a flattened sac-like appearance.
   
4. Mitochondria- The most prominent role of mitochondria is to produce the energy currency of the cell, ATP (Adenosine triphosphate), through respiration, and to regulate cellular metabolism. Thus, they are also called "the powerhouse of the cell".
5. Plastids- Plastids are present only in the plant cell. These are the site of manufacture and storage of important chemical compounds used by the cell. They often contain pigments used in photosynthesis, and the types of pigments in a plastid determine the colour of the cell.
   
6. Ribosomes- These are complex non-membrane-bound cell organelles that are made up of RNA molecules and proteins. They are involved with the endoplasmic reticulum to synthesize proteins.
   
7. Golgi body- The main function of the Golgi body is the secretion or export of macromolecules. It is where the glycoproteins and glycolipids are formed or synthesized. The proteins which are formed within the RER are then modified and sorted for their transport to their required destination..
8. Lysosome- One of the key organelles involved in digestion and waste removal is the lysosome. These contain hydrolytic enzymes and can digest excess or worn-out organelles, food particles, and engulfed viruses or bacteria.
9. Centrosome- The main purpose of a centrosome is to organize microtubules and provide structure for the cell, as well as work to pull chromatids apart during cell division.
10. Vacuoles- It mainly stores water, sap, excretory products, and other materials not useful for the cell. The membrane helps in the transport of ions and other materials against the concentration gradient, making their concentration higher in vacuole than the cytoplasm.
11. Nucleus-The nucleus contains all the genes and controls the functions of the entire cell by regulating gene expression. This is why the nucleus is sometimes referred to as the control center, or the "brain," of the cell.
12. Chromosome- The genetic material passes from parents to child, the chromosomes are responsible for containing the genes which are passed on to the offspring during sexual reproduction.