biology

• what are the components of an animal cell

  nucleus,cell membrane, cytoplasm,ribosomes,mitochondria
• What are some differences between plant and animal cell

  permenant vacuole, cell wall,chloroplast
• Describe the features of bacterial (prokaryotic) cells 

  plasmids,flagellum,ribosomes,rings of dna,cell membrane,cell wall,cytoplasm
• what are the different scale and sizes in cells

  centimetre,millimetre,micrometre,nanometre
• what are speciallised cells

  cells that have a specific function
• what is differentiation

  when a cell changes to become speciallised to a specific function
• what are some adaptations of a sperm cell

  has a long tail so it can move faster

  has digestive enzymes in its head so it can break through the cell membrane of the egg.
• what are some adaptations of a nerve cell

  long axon so information is passed through long distances.

  fatty sheaths which helps electrical impulses move along the nerve more quickly.
• what are some adaptations of root hair cells


  large surface area which absorbs more water and mineral ions
• what are some adaptations of a muscle cell

  lots of mitochondria to provide energy for contraction

  protein filaments slides over allowing the muscles to contract
• what are some adaptations of the phloem

  made up of living cells

  cells joined with sieve plates between them to allow the passage of substances
• what are the parts of a light microscope

  stage,objective lens,focus and coarse knob,eye piece,light source,
• what is the function of the focus and coarse knob

  to bring the image into focus so its more clear to see
• what are some advantages of a light microscope

  more cheap

  dosent require experience
• what are the disadvantages of electron microscope

  more expensive

  needs experience
• what are the advantages of an electron microscope

  higher magnifcation

  higher resolution

  can be used in a labatory
• what is the equation for the magnification

  size image/real image
• what are some of the conditions requires for bacteria to reproduce

  oxygen

  nutrients

  moisture
• how long does it take for bacteria to multiply

  20 minutes
• what is binary fission

  reproducing bacteria
• what are the steps for binary fission

  dna is replicated

  cell starts to expand and the dna is split and moves to the oppisite sides

  cytoplasm and cell wall divides to form two identical cells
• how do u calc the mean div time

  time spent dividing/mean division time
• calc the number of cells produced

  2 to the mean division time
• what is the importance of aseptic techniques

  We use aseptic techniques to reduce contamination so unwanted pathogens are not produced which could alter the results or effect someones health.
• what are some aseptic techniques

  Wash your hands with antibacterial hand soap or clean the surface with antibacterial spray.

  The petri dish must be incubated at 25 celcius to restrict the growth of harmful pathogens
• how to calculate cross sections

  pi squared
• what is the process of the cell cycle and mitosis

  During the cell cycle the genetic material is doubled and then divided into two identical cells. Before a cell can divide it needs to grow and increase the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome. In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides. Finally the cytoplasm and cell membranes divide to form two identical cells
• what is the importance of mitosis

  Cell division by mitosis is important in the growth and development of multicellular organisms.
• what is a stem cell

  A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type, and from which certain other cells can arise from differentiation.