IB ESS HL 2.1.29 Life Cycles and r/K Strategies Question Bank
Compare r-selected and K-selected strategies using reproductive output, survival and community stability.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Compare r-selected and K-selected strategies using reproductive output, survival and community stability.
Draw a sketch graph showing a typical survivorship curve for a "K-strategist" species.
Survivorship curve:

[1] for correctly labelled axes;
[1] for the correct shape of the graph;
[1] for both axes labelled correctly / x-axis age/% of maximum lifespan and y-axis number of survivors/individuals/number of survivors per 100/1000;
[2 max]
Outline one reason for the shape of the curve from part 3(a)(i) above.
Part 3(a)(i) asks for a typical survivorship curve for a K-strategist species. Use that curve when explaining its shape.
Any one of the following:
most K species survive until after offspring bearing age/maturity; death rate increases near the end of the lifespan; a few K individuals will die at a young age;