Hard

• how does mieosis differ from mitosis?

  • sexual
  • gametes
  • testes
  • 23 chromosome
  • 4 cells produced
  • 2 divisions
• when is the rate of transpiration the greatest?

  • warm with low humidity
• describe mitosis?

  • DNA is replicated
  • the replicated chromosomes are pulled apart
  • the cytoplasm divides into two cells
  • the set of chromosomes in each new cell are identical to one another
• 1 cm =

  • 10000 micrometres
• why does every organism have an even number of chromosomes

  • as chromosomes are in pairs
• why is division of body cells important?

  • for asexual reproduction
• DNA

  • it is a code
  • sequence of amino acids
• plasma

  carries waste such as urea around the body
• platelets

  clots the blood
• salivary glands

  • found in the mouth and produces amylase
• stomach

  • produces protease
• pancreas and small intestine

  produces:

  • protease
  • amylase
  • lipase
• Enzyme breakdown

  • break down large insoluble molecules
  • into small insoluble molecules
  • so they can be absorbed
• amylase breaks down carbohydrates into

  • glucose
• protease breaks down protein into?

  • amino acids
• lipids break down fat into?

  • fatty acids and glycerol
• active transport

  • the movement of particles against the concentration gradient which requires energy
• stents

  advantage

  • widens the lumen to increase blood flow
  • rapid recovery from the operation

  disadvantage

  • rise of blood clotting or infection
• statins

  advantage:

  • decreases bad cholesterol
  • maintains blood flow to heart muscle cells

  disadvantage:

  • there are some side effects
  • drug needs to be taken long term
• coronary arteries

  • supply the heart muscle with blood
  • with O2 and glucose so it can contract for aerobic respiration
• two advantages of stem cells compared to embryonic stem cells

  • wont be rejected
  • doesnt involve destroying an embryo