Question

How does mutation, random fertilization, and crossing over contribute to genetic variation?

Answer 1

Mutation are two types somatic and germ cell mutation...as there is mutation in germ cell it will alter the normal behavior and produce variation !

random fertilization also causes variation as different setup of genes meets with another different...so chances of variation increases !

and third crossing over is in meiosis when chiasmata forms....so in this two homologous chromosome attach to each other and on separation ... some part exchange so leads to variation !