Year 9 · Summer Second Half

Biology

3 lessons from 1 unit.

Unit B11 · lessons 2 to 4 of 4

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 selectionProcessNot one animal in the population changes. The population changes, because of which animals had offspring — and that is a completely different mechanism from the one most people imagine.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