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FUNDAMENTAL UNIT OF LIFE

FUNDAMENTAL UNIT OF LIFE. CELLS. CELL THEORY . All living organisms are composed of one or more cells. The cell is the basic unit of structure, function, and organization in all organisms. All cells come from preexisting, living cells.

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FUNDAMENTAL UNIT OF LIFE

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  1. FUNDAMENTAL UNIT OF LIFE

  2. CELLS

  3. CELL THEORY • All living organisms are composed of one or more cells. • The cell is the basic unit of structure, function, and organization in all organisms. • All cells come from preexisting, living cells. • Usually credited to Matthias Schleiden and Theodor Schwann. However, many other scientist like Rudolf Virchow contributed to the theory.

  4. ROBERT HOOKE CELLS WERE FIRST DISCOVERED BY HIM IN 1665

  5. ROBERT OBSERVED : • Slice of cork resembled the structure of the honeycomb consisting of small compartments. Robert called theselittle compartments as cells. CORK COMES FROM THE BARK OF THE TREE CORK SEEN UNDER THE MICROSCOPE OF HOOKE

  6. STRUCTURE OF CELL • Cells come in all shapes and sizes. While most of the cells are spherical in shape, cells of various other shapes are also found. Most of the cells are microscopic in size, i.e. it is impossible to see them with naked eyes. Some cells are fairly large, e.g. a neuron in human body can be as long as 1 meter.

  7. COMPARING CELLS nerve cells can be 1m long human egg cell is no bigger than the dot on this i human red blood cells is 1/10 the size of a human egg cell bacterium are even smaller- 8000 can fit inside a human egg cell

  8. DIFFERENT CELLS NERVE CELL FAT CELL BONE CELL SPERM OVUM BLOOD CELL

  9. CELL TYPES PROKARYOTIC CELLS no membrane bound structures EUKARYOTIC CELLS membrane-bound structures

  10. UNICELLULAR ORGANISMS • ORGANISMS THAT HAVE A SINGLE • CELL-PROKARYOTIC CELLS. AMOEBA PARAMOECIUM CHLAMYDOMONAS

  11. MULTICELLULAR ORGANISMS • ORGANISMS HAVING MORE THAN ONE CELL TO PERFORM VARIOUS FUNCTIONS-EUKARYOTIC CELLS. PLANTS ANIMALS FUNGI

  12. CELL WALL found in plants, algae, fungi, most bacteria tough, rigid outer coverings that protect the cell and give it shape plant cell walls are mainly made of cellulose what makes the cell walls rigid? Pectin and lignin!

  13. CELL MEMBRANE Protective layer around all cells If a cell has a cell wall, then the cell membrane is inside of it what does it do? regulate interactions between the cell and the environment food particles and some molecules enter and waste products leave through the cell membrane water can move into and out of cell through the cell membrane

  14. CYTOPLASM Contains a framework called the cytoskeleton - this helps maintain or change the shape of the cell. Gelatin like substance that fills cells which is constantly moving Cytoskeleton helps some cells move cytoskeleton is made up of thin, hollow tubes of protein and thin, solid protein fibers

  15. ORGANELLES contained within the cytoplasm • What do organelles do? • process energy • manufacture substances needed by the cell • move materials • act as storage sites • are surrounded by membranes • nucleus is usually the largest organelle

  16. NUCLEUS directs all cell activities is surrounded by a membrane a nucleolus is also within the nucleus materials enter and leave through the membrane contains instructions for everything in the cell, which are found on DNA

  17. NUCLEUS

  18. ENERGY-PROCESSING ORGANELLES • cells need energy to: • process food • make new substances • eliminate wastes • communicate with each other

  19. PLANTS • food is made in green organelles called chloroplasts • contain green pigment chlorophyll • chlorophyll captures light energy that is used to make glucose

  20. ANIMALS • energy in food is stored until it is released by the mitochondria • organelles where energy is released from the breakdown of food into carbon dioxide and water • muscle cells are more active, so they contain more mitochondria

  21. GOLGI BODIES proteins are made and sent to the Golgi bodies Golgi bodies sort proteins and other cellular substances and package them into membrane-bound structures called vesicles vesicles deliver cellular substances to areas inside the cell Refrigerator - cells have membrane-bound spaces called vacuoles for temporary storage of materials (water, waste products, food, and other cellular materials)

  22. RECYCLING ORGANELLES lysosomescontain digestive chemicals that help break down food molecules, cell wastes, and worn-out parts active cells break down and recycle substances lysosome membrane keeps the chemicals from leaking into the cell when a cell dies a lysosome’s membrane disintegrates, releasing digestive chemicals that quickly breakdown the cell’s contents

  23. PRESENTED BY • LIPIKA BISWAS, TGT (SCIENCE), K.V. - BALLYGUNGE

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