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Combined Science: Biology

GCSE · Edexcel · foundation

QuestionsFlashcards

Disease
Defence Against Disease
Development of Medicines
- Antibiotics
  4
- Discovery & Development of New Drugs
  3
Non-Communicable Diseases
- Lifestyle & Non-Communicable Disease
  7
- Cardiovascular Disease
  6

The Organism in the Environment
Human Influences on the Environment
- Human Impact on Biodiversity
  6
- Benefits of Maintaining Biodiversity
  4
Cycles within Ecosystems

Gas Exchange Flashcards

All 6 cards in this deck

In gas exchange at the alveoli, which gas moves from the alveolus into the blood in the capillary, and which gas moves from the blood into the alveolus?: Oxygen moves from the alveolus into the blood; carbon dioxide moves from the blood into the alveolus.
By which process do oxygen and carbon dioxide move between the air in the alveoli and the blood in the capillaries?: Diffusion. Not osmosis (water only) or active transport.
How do thin alveolar walls adapt the alveoli for gas exchange?: The walls are one cell thick, giving a short diffusion distance, so oxygen and carbon dioxide diffuse across quickly.
How does having many alveoli adapt the lungs for gas exchange?: Many alveoli give a large surface area, so more oxygen is absorbed into the blood and more carbon dioxide is released.
Why is the lining of an alveolus moist?: So oxygen and carbon dioxide can dissolve and move across into or out of the blood.
How does the network of capillaries around each alveolus help gas exchange?: A good blood supply keeps oxygen concentration low and carbon dioxide concentration high in the blood, maintaining the concentration gradients for diffusion.