INTRODUCTION / DEFINITIONS.
Diffusion is the movement of particles of various substances from the region of their higher concentration to the region of their lower concentration,
Mitochondrion is known as power house of the cell because it produces most of the molecules of ATP (Adenosine TriPhosphate) which are required for providing energy for synthesis of new chemicals and other cellular functions.
Proteins are synthesised over ribosomes of RER while lipids are synthesised over SER.
Plasma membrane of Amoeba is flexible, with its help, Amoeba engulfs the food particles
Osmosis is diffusion of water from the region of its higher concentration (pure water or dilute solution) to the region of its lower concentration (strong solution) through a semipermeable membrane.
Endosmosis is entry of water into a system, cell or organ due to presence of hypertonic solution in it and its separation from pure water or dilute solution by a semipermeable membrance.
Cell is the functional unit of life.
It can be defined as a tiny mass of protoplasm covered by plasma membrane which is capable of performing all functions of life.
Plasma membrane is an elastic living membrane made up of lipids and proteins, whereas cell wall is a rigid non-living covering made up of cellulose.
Plasma membrane acts as a selectively semipermeable membrane which allows only selective substances to pass through it.
Cell Wall provides rigidity and protection to cell.
Chromatin is the nucleoprotein fine fibrous mass which stains strongly with basic dyes and is present as a network inside the nucleus.
Chromosome is a rod-like, stainable, condensed chromatin unit, visible at cell division and containing hereditary information in the form of genes.
Nucleolus is called little nucleus
Robert Hooke discovered the cell in 166
Nucleus controls and coordinates all the metabolic functions of the cell.
Lysosomes keep the cells clean by digesting foreign materials and worn out cell organelles.Robert Brown discovered protoplasm in 1831.
Sugar and salt increases osmotic concentration which results in passage of water osmotically through the cells .