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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

Diffusion Flashcards

All 5 cards in this deck

What is diffusion?: The net movement of particles from an area of higher concentration to an area of lower concentration, down a concentration gradient. It is a passive process.
Name two substances that move into or out of cells by diffusion.: Oxygen and carbon dioxide (also urea and some glucose).
State three factors that increase the rate of diffusion into a cell.: A steeper concentration gradient, a higher temperature, and a larger surface area of membrane.
True or false? Diffusion and osmosis are passive, so they do not need energy from respiration.: True. Only active transport requires energy from respiration.
True or false? Starch and proteins can diffuse through cell membranes.: False. They are too large to pass through the membrane; only small molecules, such as glucose and oxygen, can diffuse across.