Describe the two forms of variation found within a natural population.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2014). The mark or mark type is shown in brackets.

1. [max. 5] continuous variation ;
2. [max. 5] gradual change / range ;
3. [max. 5] between extremes ;
4. [max. 5] genes + environment ;
5. [max. 5] discontinuous variation ;
6. [max. 5] few and distinct differences ;
7. [max. 5] controlled by genes alone ;
8. [max. 5] any correct example of one or the other correctly linked ;
9. [max. 5] some variations are advantageous ;
10. [max. 5] competition;
11. [max. 5] in the organism's habitat/environment;
12. [max. 5] organism survives / differential survival / ORA ;
13. [max. 5] breeds / reproduces ;
14. [max. 5] passes on the advantage/beneficial gene/allele;
15. [max. 5] over many generations / ref. time;
16. [max. 5] continuous adaptation to the changing environment ;
17. [max. 5] evolution / natural selection / AW ;
18. [max. 5] changes that result from the environment not so important ;