Cell is a building block like …

There are three main components of a cell: (i) Cell membrane (ii) Cytoplasm (iii) Nucleus (iv) cell wall.
Cell Membrane: Cell membrane is also called plasma membrane. It makes the boundary of a cell. It is composed of protein and lipid.
Cell Wall: Cell wall is present in plant cells and in bacteria. Cell wall in plants is made up of cellulose. Cell wall gives additional strength and protection to plant cells.
Cytoplasm: A jelly-like substance is present between the cell and nucleus. It is called cytoplasm. Different cell organelles are present in the cytoplasm.
Nucleus: This is a spherical structure which is present inside the cell; usually at the centre of the cell. Nucleus is surrounded by a double membrane called nuclear membrane. A dot-like structure; called nucleolus is present inside the nucleus. Nucleus contains chromosomes which are thread-like structures.