Question

Write short notes on cell membrane cell wall nucleus nuclear membrane cyptoplasm plastids vacuole

Answer 1

a) Cell wall:
       •  This is the structure present only in plant cells.
       •  The cell wall gives rigidity to the cell. It provides toughness and strength to the plant body which stands erect in different environmental conditions.
       •  It is made up of cellulose and pectin.
b) Cell membrane:
       •  The cell membrane is a biological membrane that separates the interior of all cells from the outside environment.
       •  The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells.
       •  It consists of the phospholipid bilayer with embedded proteins.

c) Cytoplasm:
       •  It is a jelly-like fluid present between the nucleus and the cell membrane.
       •  In a prokaryotic cell, the organelles are dispersed in the cytoplasm.
       •  In a eukaryotic cell, the contents of the nucleus are separated from the cytoplasm. i.
Nucleus  
       •  The nucleus is the control centre of the cell as it controls all its activities.
       •  The nucleus is a membrane-enclosed organelle found in eukaryotic cells.
       •  The nucleus contains the genetic material of the cell in the form of chromosomes.