5 (health + disease) - exam qs

• State the term used to describe the rapid growth of a bacterial population:

  Exponential growth
• Children in the UK can be immunised against whooping cough. Suggest why outbreaks of whooping cough still occur in the UK.

  Not everyone has been immunised, immunisation is not fully effective, it can decrease with age
• Describe the response of the human body to immunisation

  It introduces an antigen that provokes an immune response as the immune system recognises it due to memory lymphocytes. Antibody production is provoked and they are specific to that antigen.
• Houseflies can be the animal vector for the disease dysentery. The disease dysentery is caused by...

  Bacterium
• Describe how a housefly can cause a person to become infected with dysentery:

  Houseflies carry pathogens so if a housefly lands on animal waste it can transfer dysentery or bacteria onto food and if infected food is eaten, the person will be infected
• Explain how the Anopheles mosquito can spread the disease malaria

  The mosquito is a vector which can carry plasmodium that can pierce the skin and transfer plasmodium to blood
• How can a change in body mass cause a person to develop type 2 diabetes?

  Increasing body mass leads to obesity which will lead to the body becoming resistant to insulin
• Describe how the human body acts in response to low glucose levels in the blood.

  Glucagon is released from the pancreas. Glycogen is converted into glucose in the liver or muscle cells. This raises blood glucose levels.
• Why can dieting be used to reduce weight in obese people?

  Dieting reduces energy consumption
• Some rats have a mutation which enables them to eat the rat poison Warfarin and survive. Suggest how the use of Warfarin could lead to an increase in the number of rats with this mutation.

  Rats with the mutation will breed or reproduce and pass on the allele which makes the offspring resistant to Warfarin
• Some sexually transmitted infections can be diagnosed by testing urine samples. These tests use monoclonal antibodies that bind to an antigen on the pathogen. Describe how a monoclonal antibody can be developed and used to detect an STI using a urine sample:

  Isolate an antigen from the pathogen which causes the STI. Collect lymphocytes producing an antibody to the STI antigen. Fuse the lymphocyte with a myeloma cell to produce a hybridoma which produces a monoclonal antibody against the STI antigen. Attach this antibody to a coloured indicator and incorporate it into a test strip.
• Explain how increase in number of insulin units injected would affect blood glucose concentration:

  An increase in the units would cause more glucose to be converted to glycogen and be stored in the liver or muscles. This could lead to the blood glucose levels becoming critically low and the person will become hypoglycemic
• Explain why an underactive thyroid could cause this patient to have an increased body mass:

  The thyroid gland produces thyroxine which helps regulate metabolic rate. An underactive thyroid would cause less thyroxine to be produced and the metabolic rate will drop meaning less energy is available for tasks and more fat is stored so the person gains body mass.
• 2 reasons for change in blood glucose concentration:

  Insulin being released, exercise, eating food
• What is excess blood glucose converted into?

  Glycogen in the liver
• Explain how a type 2 diabetic can regulate their blood glucose concentration:

  Exercise to reduce glucose levels, control diet or take medication
• What type of medication can be used to treat athlete's foot fungus?

  Antifungal
• What happens in the body when blood glucose is high?

  Insulin is released from the pancreas which converts the excess glucose into glycogen which is stored in the liver and blood glucose levels are reduced
• What happens in the body when blood glucose is low?

  Glucagon is released form the pancreas which converts glycogen from the liver into glucose and blood glucose levels are raised.
• How are monoclonal antibodies used in medical diagnosis?

  Pregnancy testing, locating blood clots, locating position of cancers
• Who first developed vaccination?

  Edward Jenner
• What are the molecules on pathogens that cause an immune response called?

  Antigens
• Describe the steps in producing monoclonal antibodies:

  Inject a mammal with an antigen and select lymphocytes that produce specific antibodies that fuse with tumour or myeloma cells to produce a hybridoma which divides isolating antibodies
• What is the advantage of using monoclonal antibodies to treat cancer?

  Antibody only attaches to cancer cells which alerts the immune system targeting the cells
• What is the type of cell that produces monoclonal antibodies used to treat cancer?

  Hybridoma