Organisation

• white blood cells


  can change shape to engulf microorganisms

  produce antibodies

  produce antitoxins
• Plasma


  carries everything in the blood
• Veins


  Blood is at low pressure

  Bigger lumen to help blood flow

  Valves keep blood flowing in one direction
• Capillaries


  Wall is one cell thick

  Permeable walls

  Very small lumen
• Lipase


  Converts Lipids into Fatty acids and Glycerol

  Made in Pancreas and Small Intestine
• Protease


  Proteins into Amino Acids

  Made in Pancreas and Small Intestine
• Carbohydrase


  Starch into Simple Sugars

  Made in Salivary Glands, Pancreas and Small Intestine
• Biuret Test


  Tests for Proteins

  Blue to Purple if positive
• Iodine Solution Test


  Tests for Starch

  Browny Orange to Blue/Black if positive
• Benedicts Test


  Tests for Lipids

  Blue/Black to Brick Red if positive

  Test uses warm water bath
• Arteries


  Walls are strong and elastic

  Walls are thick

  Carry the blood away from the heart
• Bile


  Emulsifies fats

  Neutralises stomach acid

  Produced in the liver

  Stored in the gall bladder

  Released into the small intestine
• Platelets


  Involved in blood clotting

  Lack of can cause excessive bleeding and bruising
• Xylem Cell


  Specialised for transporting substances around the plant

  Long and joined end to end to form tubes

  Hollow in the centre
• Phloem Cell


  Specialised for transporting substances around the plant

  Long and joined end to end to form tubes

  Few subcellular structures
• What do Villi do?


  increase the surface area of the intestine so digested food is absorbed much quicker into the blood
• Alveoli Adaptations


  Large surface area

  One cell thick

  Good blood supply

  Moist lining for dissolving gases
• Where carbon dioxide diffuses into the plant


  Stomata
• Guard Cell function


  Control the size of the stomata

  Open and close it
• benedicts tests uses a water bath
• 2 types of tumours

  benign

  malignant
• how do malignant tumours spread


  cells break off and travel in the blood stream
• what is cancer caused by


  uncontrolled growth and division
• lifestyle risk factors for developing cancer


  smoking

  UV exposure

  obesity

  viral infection
• faulty genes can be inherited which makes you more susceptible to cancer. this is a genetic risk factor
• benign tumour

  non cancerous tumour

  grows until theres no more room

  stays in one place

  isnt normally dangerous
• malignant


  cancerous tumour

  cells break off and travel in the bloodstream

  spreads to neighbouring healthy tissues

  forms secondary tumours

  can be fatal
• plant organs are made of tissues
• epidermal tissue

  covers the whole plant

  covered in waxy cuticle which helps prevent water loss through evaporation
• palisade mesophyll tissue

  where most photosynthesis happens

  lots of chloroplasts

  near the top of the leaf where they can get the most light
• spongey mesophyll tissue

  contains big air spaces to help gases diffuse in and out of the cells

  increases the rate of diffusion in gases
• meristem tissue

  found at the growing tips of roots and shoots

  able to differentiate allowing the plant to grow
• upper epidermis

  is transparent so light can pass through to the palisade layer
• lower epidermis

  full of stomata which let $CO_2$ diffuse directly into the leaf
• humans have a double circulatory system

  • right ventricle pumps deoxygenated blood from the heart to the lungs. the blood returns to the heart
  • the left ventricle pumps oxygenated blood to the other organs. deoxygenated blood returns to the heart to be pumped to the lungs
• heart walls are made of muscle tissue
• valves

  prevent the blood from flowing backwards
• how the heart uses it's 4 chambers

  • blood flows into the atria from the vena cava and the pulmonary vein
  • the atria contract, pushing the blood into the ventricles
  • the ventricles contract, forcing the blood into the pulmonary artery and aorta, out of the heart
  • the blood flows to the organs through arteries and returns through the veins
  • the atria fills again and the cycle starts over
• the pacemaker

  a group of cells which control the resting heart rate

  • produce an electric impulse which causes the surrounding muscle cells to contract
• artificial pacemaker

  produces an electric current

  keeps the heart beating regularly