Cell biology

• What do animal cells have?

  Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
• What do plants cells contain

  Nucleus, Cell membrane, Cytoplasm, Mitochondria and Ribosomes, Cell wall, Chloroplasts and Vacuole.
• What do bacteria cells contain


  cell wall, cell membrane, cytoplasm, ribosomes plasmids and circular strand on dna
• cell membrane function


  controls what substances can go in and out of the cell
• Nucleus function


  Contains genetic information/dna
• Ribosome function


  site of protein synthesis
• Cytoplasm function


  Where all chemical reactions take place
• Mitochondria function


  Provides the cell with the energy it needs to function
• cell wall function


  For structure and support
• Chloroplast function


  photosynthesis
• permanent vacuole function


  Contains cell sap mixture of salts sugar and water
• flagella function


  propel the bacteria
• plasmid function


  Extra genes antibiotic resistance
• Circular strand of dna function


  Genes they need to survive/ reproduce circular chromosome/ nucleoid
• Sperm cell function


  to fertilize an egg
• How is a sperm cell adapted to its function?


  - long tail so it can swim to the egg

  - lots of mitochondria for energy for swimming
• muscle cell function


  contraction
• How is muscle cell adapted to its function


  Is long so it has room to contact contains a lot of mitochondria for energy for contracting
• Nerve cell function


  To carry electrical signals from one part of the body to another
• How is a nerve cell adapted to its function?

  Is long has branches
• Root hair cell function


  Absorbs water and mineral ions from the soil.
• How is a root hair cell adapted for its function?

  It has a large surface area to increase osmosis of water
• Pholem cell function


  Transport sugars made in the leaves to other part of the plant
• How is phloem adapted for its function?


  Phloem cells are elongated and have sieve plates (holes) between cells so that the cell sap can move from cell to cell allowing the phloem to act as a tube. Phloem cells have less organelles than other plant cells so there is more space in the cells for them to act as tubes
• Xylem function


  Transports water and dissolved minerals ions from the root up to all the other parts of the plant
• How is xylem adapted to its function?

  Hollow tubes strengthened by lignin
• Tissue definition


  group of cells with similar structure and function
• Organ definition


  Collections of different tissues that perform specific functions
• Organ system definition


  organs working together in systems to form organisms
• Organism definition


  A living thing
• Explain the importance of cell differentiation


  Allows the production of different tissues and organs that perform vital functions in the human body
• electron microscope


  An electron microscope has a much higher resolution and magnification than a light microscope so smaller things can be seen in more detail
• light microscope


  Light microscope can be used to look at cells they let us see large sub cellular structures
• Microscopy practical


  1) start with the lowest powered lens then move the stage up with the course adjustment knob

  
  

  2) look down the eyepiece and adjust the focus with the adjustment knobs use the course one first

  
  

  3) to see the slide with a greater magnification swap to a higher powered lens and refocus

  
  

  When drawing your observations

  .use a sharp pencil

  .draw unbroken lines

  .label important features

  .include a magnification scale
• binary fission steps


  1. DNA Replication

  2. Chromosome Segregation (when the replicated chromosomes move to different ends of cell)

  3. Separation (new plasma membrane growth, cytoplasm divide, and new cell walls form around the new cells)
• Where can bacteria be grown?

  In a nutrient broth solution or as colonies on an agar gel plate
• Why must Petri dishes and culture media be sterilised before use?

  To kill any bacteria already present.
• Why must inoculating loops be sterilised by passing them through a Bunsen burner flame?


  To kill any bacteria present on the inoculating loop.See an expert-written answer!We have an expert-written solution to this problem!
• Why must the lid of the Petri dish be secured with adhesive tape and stored upside down?

  This prevents condensation from dropping onto the surface of the agar
• Why are microorganism kept at 25°C at a school Lab

  Because harmful microorganisms are more likely to grow above this temperature