2020

• most food molecules are absorbed in the

  small intestine
• electron microscope has

  greater magnification
• capillaries have

  villi
• • uses of sugar
  • respiration
  • to form glycogen
• • villi adaptation
  • they have many microvilli to increase surface area
  • the wall of villus is one cell thick and capillaries are close to the surface so their is a short pathway
  • cells have lots of mitochondria where energy is transferred
• dangers if being obese

  -CHD

  -type 2 diabetes

  -cancer
• • how the balance between mass of food eaten and the amount of exercise a person does controls body mass
  • they have an increased energy intake if they eat more food
  • if they exercise more, more energy is released
  • if energy intake = energy transferred, then body mass stays the same
• • what happens to the body during vigorous exercise
  • increased breathing rate
  • increased breath volume
  • increased heart rate
  • so increased blood flow to muscles
  • and glycogen is converted to glucose
  • insufficient oxygen is supplied so lactic acid is formed during anaerobic respiration
  • lactic acid makes muscles tired
• • what happens to the body AFTER exercise
  • heart rate slowly decreases
  • this is to pay back oxygen debt to break down lactic acid
  • lactic acid is converted back into glucose
  • some is transported to the liver
• • differences between bacteria and plant cell ( and vice versa )

  1. bacteria cell is smaller
  2. bacteria cell does NOT have chloroplasts
  3. bacteria cell may have plasmids
  4. bacteria cell does not have a nucleus
  5. bacteria cell does not have mitochondria
• • how does a vaccine work to prevent a disease
  • vaccine is an inactive pathogen which is injected
  • white blood cells are stimulated to produce antibodies
  • due to memory cells, on re-exposure specific antibodies are made very quickly
  • pathogens are killed and thus don’t produce a large enough population to catch the disease
• • why is salmonella more common in summerhotter weather = bacteria reproduce faster
• • how can oxygen production be used to show the rate of photosynthesiswhen more oxygen is produced in a given time, the rate of photosynthesis is faster
• • why are low doses of the drug used in Phase 1 of Clinical Trials
  • to reduce risk
  • to look for side effects
• • why are healthy volunteers used in Phase 1 of Clinical Trials
  • drug side effects are easier to identify
  • its too risky for an ill person to be a volunteer
• • one reason why the results must be reviewed by other scientists
  • avoid bias
  • avoid false claims