Sherpa

Existing user?

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: Osmosis in Potatoes Flashcards

All 5 cards in this deck

What is measured in the potato osmosis core practical?: The mass of each potato chip before and after it is left in the solution (blotted dry each time), so the percentage change in mass can be worked out.
Name three variables that must be controlled in the potato osmosis investigation.: Same temperature; same volume of solution; same size/mass of potato chip.
(Also same time left and same method of blotting dry.)
In an osmosis investigation, what does the solution concentration at which there is no change in mass tell you?: The concentration inside the cells is the same as outside — the isotonic point.
What is the equation for the percentage change in mass in an osmosis investigation?: percentage change in mass = (final mass − initial mass) ÷ initial mass × 100
A negative answer means mass was lost.
In the potato osmosis core practical, why is the percentage change in mass worked out instead of just the change in mass?: The potato pieces may not start with the same mass, so a percentage lets their results be compared fairly.