What are some things that might cause a mutation

Genetic mutations in the DNA, that are kept in ur DNA and passed down from generation to generation. It is kind of like blue eyes. The environment can cause a mutation, or ur diet. There are many factors. 

A chromosome may be added causing a trisomy. Or a chromosome may be lost causing a monosomy. Most mutations will form due to chromosomal patterns failing.

The answer your looking for is a food chain grid. it describes how nature can support itself and survival of the fittest comes into play..