Aqa Biology Unit 1

Revision notes for Biology exam GCSE AQA

41 cards   |   Total Attempts: 182
  

Cards In This Set

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Define metabolic rate
  • The rate at which reactions take place within the body, particularly within cellular respiration.
What is a balanced diet?
  • A diet that includes everything needed to keep the body healthy
Why do different people need different diets?
  • People need different amounts of energy because the metabolic rate varies between person to person
Which food groups are used by the body to release energy and build cells?
  • Carbohydrates, fats and proteins
Why are mineral ions and vitamins needed?
  • They allow the body to work properly and keep healthy
What happens if someone has an unbalanced diet?
  • They become malnourished
Factors that affect someone’s metabolic rate:
  • Age
  • Gender
  • Proportion of muscle to fat
  • Amount of exercise
  • Inherited genes
  • What can obesity lead to?
  • Type 2 diabetes
What can happen if people eat too little food?
  • Bones become brittle, women's periods may stop, find it hard to walk
Why do you need 'good' cholesterol? (HDL)
  • For cell membranes and to make vital substances
  • It decreases the risk of heart disease and flows in the bloodstream removing 'bad' cholesterol (LDL)
What happens if you have high levels of 'bad' cholesterol? (LDL)
  • Increased risk of heart disease and strokes
What do Pathogens cause?
  • Infectious diseases
What are Pathogens?
  • They are tiny microorganisms which are usually bacteria or viruses.
How do bacteria or viruses make you fell ill?
  • Once they enter the body they produce toxins which are kinds of poisons. Viruses are smaller than bacteria and reproduce inside cells, the damage to cells make you feel ill as well.
Who discovered the washing hands reduced the risk of spreading diseases?
  • Semmelweiss
What defense mechanisms does the body have against pathogens?
  • The skin, trapped by mucus, killed by stomach acid and white blood cells