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Combined Science: Biology

GCSE · Edexcel · higher

QuestionsFlashcards

Disease
Defence Against Disease
Development of Medicines
- Antibiotics
  4
- Discovery & Development of New Drugs
  6
Non-Communicable Diseases
- Lifestyle & Non-Communicable Disease
  8
- Cardiovascular Disease
  6

The Organism in the Environment
Human Influences on the Environment
- Human Impact on Biodiversity
  6
- Benefits of Maintaining Biodiversity
  6
Cycles within Ecosystems

Human Defence Responses Flashcards

All 6 cards in this deck

How does the skin defend the body against pathogens?: It acts as a physical barrier that stops pathogens entering the body.
If it is cut, a blood clot/scab seals the wound to prevent bacteria entering.
What is the role of mucus in defending the airways against pathogens?: It is a sticky physical barrier that traps pathogens and dust before they reach the lungs.
What do cilia in the airways do as a defence against pathogens?: They beat to sweep mucus containing trapped pathogens up to the throat, where it is swallowed.
What is the role of lysozymes in tears?: They are enzymes that destroy bacteria by breaking down their cell walls.
How does hydrochloric acid in the stomach act as a chemical defence?: Its low pH kills pathogens in swallowed food and mucus.
True or false? Mucus and cilia are chemical defences against pathogens.: False. They are physical barriers; lysozymes and hydrochloric acid are the chemical defences.