A group of ecologists used the mark-release-recapture method to estimate the population size of red squirrels in a woodlands nature reserve.
In the first sample, they captured, marked, and released 454545 squirrels.
Two weeks later, they captured a second sample of 404040 squirrels from the same area of the reserve. The ecologists calculated that the total population of red squirrels in this reserve was 360360360.
Using this information, calculate how many squirrels in the second sample were marked.
11 exam-style questions on AQA A Level Biology Populations in ecosystems (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.