Year 9 · Summer Second Half
Biology
3 lessons from 1 unit.
Unit B11 · lessons 2 to 4 of 4
Evolution, extinction and biodiversity
B10 ended with variation and what a species is. This unit is what variation DOES over time. Which variation helps depends entirely on the conditions, and the conditions change — so populations change, some species run out of the variation they need, and the variety that is left turns out to be the thing worth protecting.
- 02Natural selectionProcessOver many generations, a whole species can change its shape. What actually makes that happen?Open this lesson
- 03When the environment changes: extinctionSystemMore than nine in ten of all the species that have ever lived are gone. Extinction is not a failure of the system — it is the system, and the question worth asking is what makes a species vulnerable to it.Open this lesson
- 04Biodiversity and gene banksSystemVariation is what a population has instead of a plan. Keeping it — in the wild where possible, in a freezer where necessary — is the closest thing biology has to an insurance policy.Open this lesson
Back to all three sciences this half term The whole KS3 Biology course