B1 a -c

B1 a -c

1. C

   • Any organism which causes disease is called a pathogen
   • Hydrochloric acid in the stomach kills pathogens in our food
   • A vector is an animal which carries an organism that causes disease
   • Cancer is caused by cells which have lost the ability to stop dividing
   • A placebo is an inactive substance containing no medicine is used as a control when testing new drugs

2. B

   • Excess carbohydrates from the diet are stored in the liver as glycogen or converted into fats
   • Excess animo acids from the diet cannot be stored and are excreted in the urine
   • Protein is needed for growth and repair
   • Kwashiorkor sufferers have very little protein in their blood leading to swelling of the abdomen
   • BMI (body mass index) = mass (kg) ÷ (height in m)2
     • Underweight = under 18.5
     • Normal = 18.5 - 25
     • Overweight = 25 - 30
     • Obese = over 30
   • EAR = estimated average requirement
     • Protein EAR = body mass (kg) x 0.6

3. A

   • Blood pressure
     • High blood pressure can cause strokes
     • Blood pressure is caused by the contraction of the hear
     • Low blood pressure can cause dizziness and fainting
     • Diastolic pressure = the minimum pressure when the heart relaxes
     • Systolic pressure = the maxium pressure the heart produces when it contracts
   • Cholesterol can stick to the walls of arteries slowing down or blocking the flow of blood