B1 set pieces

• Mitosis and the cell cycle

  • Increase the number of mitochondria and ribosomes
  • genetic material is replicated
  • Chromosomes are pulled to each of the cell
  • Cytoplasm and cell membrane divide to form two identical daughter cells
• Adaptations of organs for diffusion

  (examples include lungs, small intestine, gills, roots, leaves)

  • large surface area
  • thin membrane to allow faster rates of diffusion
  • good blood supply well ventilated
• The role of Bile in digestion

  • Bile is made in the liver and stored in the gallbladder
  • it is alkaline to neutralise stomach acid
  • it emulsifies fat to form small droplets, increasing the surface area for lipase to act
• Digestive enzymes

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• Coronary heart disease

  • Layers of fatty materials built up inside the coronary arteries, narrowing them
  • this reduces the blood flow through the coronary arteries, resulting in a lack of oxygen for the heart muscle
• Faulty heart valves

  • Can develop leaks, causing heart failure, strokes, blood clots or death due to the sudden cardiac arrest
  • treated with mechanical or biological replacement valves
• Heart failure

  Treated with a heart transplant or a temporary artificial heart while awaiting transplant
• Vaccinations

  • Vaccinations involves introducing small quantities of dead or inactive pathogen into the body to stimulate the white blood cells to produce antibodies
  • If the same pathogen enters the body, the white blood cells respond quickly to produce the correct antibodies, preventing infection
• Drug testing

  • New drugs are extensively tested for toxicity, efficacy, and dose
  • pre-clinical trials are done in a lab using cells, tissues and live animals
  • clinical trials are done using healthy volunteers and patients