10. Experiment design
What I’ve Done
1. Cut leaves into three
sizes
2. Place leaves in test
tubes
3. Add 10 aphids to each
tube
What You’ll Do
1. Count the number of
adult aphids
2. Count the number of
baby aphids
3. Switch to a tube with
a different leaf size
and repeat 1 and 2
16. Experiment design
What You’ll Do
1. Count and record the number of adult aphids
2. Count and record the number of baby aphids
3. Add these together for the population density
(What is the unit for area?)
4. Calculate the number of births and deaths
5. Switch to a tube with a different leaf size and
repeat 1 and 2
18. Review
• What is a population?
• What is population density?
• What factors affect population density?
• How does food affect aphid population
density?