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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

Core Practical: Investigating Light & Photosynthesis Flashcards

All 5 cards in this deck

In the core practical with pondweed, how is the rate of photosynthesis measured?: Count the number of bubbles (or measure the volume of oxygen) produced in a set time.
Give two ways to improve the quality of results when the oxygen bubbles are hard to count.: Collect the gas in a syringe/measuring cylinder and measure its volume; or repeat at each light intensity and calculate a mean.
How is temperature kept constant in the light intensity core practical?: Use a heat shield between the lamp and the tube, and a thermometer, adding cold water as necessary.
In the light intensity core practical, how is the light intensity reaching the pondweed changed?: By moving the lamp to different distances from the pondweed: the further away the lamp, the lower the light intensity.
Why is sodium hydrogencarbonate added to the water in the light intensity core practical?: It releases carbon dioxide, so CO₂ is not a limiting factor and stays the same at every light intensity.