Biology

• Cell differentiation

  All cells start as single cells but certain characteristics can be added to specialise the cell.
• Magnification of a cell equation

  Image height / object height
• Mouth


  Mechanical breakdown
• Salivary glands


  Produce amylase
• Liver


  Produces bile
• Gall bladder


  Stores bile
• Small intestine

  Moves glucose to the blood
• Pancreas


  Produces enzymes
• Large intestine


  Removes excess water
• Chambers in a heart

  Right and left ventricle and atrium
• The blood enters the heart through the ............. it leaves the heart through the ............ and then re enters the heart through the ........... It is taken through the heart and out of the ........

  Vena cava, pulmonary artery, pulmonary vein, aorta
• Stem cells are used to...

  Treat illness and injury's
• Disadvantages of stem cells

  Killing potential human life, human embryos destroyed, religious reasons
• Nucleus contains ....... which contain DNA.

  Chromosomes
• Movement of water through a partially permeable membrane from a high to low concentration

  Osmosis
• Movement of water through a membrane from a low to high concentration


  Active transport
• Movement of substances from a high to low concentration

  Diffusion
• .......... diffuses into the ....... where it can be breathed out.

  Carbon dioxide, blood
• ........ diffuses out of the blood so it can go around the .........

  Blood, body
• Cross section of a leave

  Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis, stomata and guard cell
• Carry's food from leaves down to roots

  Phloem
• Carry's water from roots up to leaves

  Xylem
• 3 things not in an animal cell but are in a plant cell

  Cell wall, vacuole, chloroplast
• Cardiovascular disease


  Fat builds up in coronary artery causing blood clots which can block artery and restrict oxygen getting to cells. Cells die causing heart attack.
• Causes of cardio vascular disease

  Smoking, high salt/fat diet, high blood pressure
• Artery


  Thick cell walls, thin lumen to carry blood at high pressure.
• Veins


  Thin cells walls, thick lumen to carry blood at low pressure
• Capillaries


  Wall one cell thick, large lumen to increase rate of diffusion
• Function of red blood cells

  Carry oxygen
• Function of white blood cells

  Kill bacteria
• Platelets


  Help form blood clots
• Sperm are specialised for

  Reproduction
• Nerve cells are specialised for

  Rapid signalling
• Root hair cells are specialised for

  Rapid absorption
• Chromosomes


  Contain DNA and carry genes
• Osmosis practical


  Measure mass of potatoes. Put in water. Leave 24 hours, measure mass again. Increased mass means drawn in water by osmosis. Decreased mass means drawn out water by osmosis.
• Dependent variable of osmosis practical

  Mass of potato
• Independent variable of osmosis practical

  Concentration of water
• Control variable of osmosis practical

  Everything apart from concentration and mass of potatoe
• Why do we repeat experiments

  Reduce the likelihood of a random error and get a more accurate mean average