THE FUNDAMENTAL UNIT OF LIFE
ROBERT HOOKE Cells were first discovered by Robert Hooke, in1665. He observed a thin slice of cork under his self designed microscope. This slice of cork resembled the structure of the honeycomb consisting of small compartments. He named these compartments as cells. small
ROBERT OBSERVED 2s CORK COMES FROM THE BARK OF THE TREE HONEY COME
UNICELLULAR ORGANISMS AMOEBA CHLAMYDOMONAS
MULTICELLULAR ORGANISMS ANIMALS FUNGI PLANTS
CELL chloroplasts mitochondria nucleus bosomes endoplasm reticulum golgi body membrane L A cell is the smallest unit that is capable of performing life functions.
CELL The shape and size of cells are related to the specific function they perform. Each living cell has the capacity to perfo! certain basic functions. Cell contains a specific component called organelles. Each kind of cell organelle performs a special function. All cells are found to have the same organelles, irrespective of their function and which organism they are found in.
CELL MEMBRANE OR PLASMA MEMBRANE It is the outermost covering of the cell that separates the contents of the cell from the external environment. A Typical Euka ryote Cell lucleus. DNA Allows the entry and exit of materials in and out of the cell.It also prevents the movement of some other material and is therefore called a selectively permeable membrane. ytoplasm Cell Wa Ribosomes Golgi Body Cell Membrane Mitochondria The plasma membrane is flexible and is made up of organic molecules like proteins and lipids.
DIFFUSION Gaseous exchange takes place from a region of higher concentration to a region of low concentration. Diffusion low concentration high concentration D solute
OSMOSIS Osmosis Selectively Pemeabile Membrane High Water Conoentration Low Water Concentratin The movement of water from a region of high water concentration through a semi- permeable membrane to a region of low water concentration
HYPOTONIC SOLUTION Hypotonic solution is the solution surrounding the cell which has higher water concentration than that in the cell. Water molecules are free to pass across the cell membrane in both directions, but more water will come into the cell than will leave The net result is that the water enters the cell and the cell is likely to swell up. % Salt Water move into the cell
HYPERTON C SOLUTION When the medium surrounding a cell has lower concentration of water than that in the cell it is said to be hypertonic. Water crosses the membrane in both the directions, but this time more water leaves the cell than enters it. Therefore the cell will shrink. . . 20%s". Sutter then ue ut of the ce Water mo