SME
Grade 9 Science
Population growth and carrying capacity
The main lesson, then each kind of problem it solves.
Population growth and carrying capacity
Main lesson
Births, deaths and migration
Use this for “A herd of 500 deer has 90 births, 40 deaths, 10 arrivals and 20 departures in a year. What is its new size?”
Doubling time
Use this for “Bacteria double every 15 minutes. How many are there after 2 hours, starting from 40?”
Density-dependent or density-independent?
Use this for “Habitat loss crowds a population. Which limiting factor grows stronger?”
Bacteria growing in a flask
Use this for “Why does the number of bacteria level off and then fall?”
Two species, one food
Use this for “Two protist species grow together in one dish. Which one wins, and why?”