topic 1

• Cell


  Basic unit of life
• Prokaryotic


  Cells that do not have a nucleus (Bacteria)
• Prokaryote


  A prokaryotic cell (single celled organism)
• Eukaryotic: Cell with a nucleus (All plant and animal cells)
• Eukaryote


  An organism made up of eukaryotic cells
• Nucleus: The part of the cell containing DNA and RNA and responsible for growth and reproduction
• Cytoplasm: A jellylike fluid inside the cell in which the organelles are suspended
• Cell membrane: A thin, flexible barrier around a cell; regulates what enters and leaves the cell
• Mitochondria: An organelle in which respiration and energy production occur
• Ribosomes


  Where proteins are made
• Cell wall: A rigid structure that surrounds the cell membrane and provides support to the cell
• Vacuole: Cell organelle that stores materials such as water, salts, proteins, and carbohydrates
• Chloroplast: Where photosynthesis occurs, making food. Full of green chlorophyll
• Plasmid


  A small ring of DNA
• Animal cell parts

  Nucleus, Cytoplasm, Cell membrane, Mitochondria, Ribosomes
• Plant cell parts: Nucleus, Cytoplasm, Cell membrane, Mitochondria, Ribosomes, Cell wall, Vacuole, Chloroplast
• Bacteria cell parts: Cytoplasm, Cell membrane, Cell wall, Plasmids, Single circular strand of DNA
• Microscope: Used to see things too small to see with the naked eye
• Light microscope: Uses light and lenses to magnify a specimen, used to view individual cells and large sub-cellular structures
• Electron microscope: Uses electrons to form a highly magnified image of a specimen, used to view small sub-cellular structures like the insides of chloroplasts and mitochondrias
• Magnification


  Image size / Real size
• Differentiation: The process by which a cell changes to become specialised for its job
• Sperm Cell


  The cell specialised for reproduction
• Nerve Cell


  The cell specialised for rapid signalling
• Muscle Cell


  The cell specialised for contraction
• Root Hair Cell: The cell specialised for absorbing water and minerals
• Phloem and Xylem Cells: The cells specialised for transporting substances
• Chromosomes: A cellular structure carrying genetic material, found in the nucleus consisting of one very long DNA molecule and associated proteins
• 2 copies: Each chromosome has _______________ (one from the father, one from the mother)
• 23


  Humans have ___ pairs of chromosomes
• Cell cycle: Makes new cells for growth, development and repair. Only happens in eukaryotic cells
• Cell cycle stage 1: DNA is spread out in to long strings
• Cell cycle stage 2: Before dividing, the cell grows to increase the number of organelles
• Cell cycle stage 3: The cell duplicates its DNA (one for each new cell) and forms X shaped chromosomes
• Cell cycle stage 4: The chromosomes line up at the centre of the cell to be pulled apart by cell fibres
• Cell cycle stage 5: Membranes form around each set of chromosomes, forming nuclei
• Cell cycle stage 6: The cytoplasm and cell membrane divide and 2 identical daughter cells have been created
• Binary Fission: A form of asexual reproduction in which one prokaryotic cell (single celled organism) divides to form two identical cells.
• Binary Fission stage 1: The circular DNA and plasmid replicate
• Binary Fission stage 2: The cell gets bigger and the circular DNA strands move to opposite ends of the cell