Brainlag PlusSurface area to volume ratios, Punnett-square probabilities, expected numbers, doubling bacteria, BMI and correlation.
Ratios and chances
- Surface area to volume: a 2 cm cube has 24 cm² and 8 cm³, ratio 24 ÷ 8 = 3. Smaller objects have bigger ratios.
- A Punnett square has four equally likely boxes: Aa × Aa gives aa in 1 of 4, so 25%.
- From a ratio 3 : 1 and 400 offspring, expect 300 : 100.
- Bacteria double every division: after n divisions there are 2ⁿ times as many.
A correlation in data does not prove that one thing causes the other.
The rest of this lesson and its 9 practice questions are in Plus.
Screen 1 of 1, free to read.
- 9 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards