Independent and crossing overWatch
Can anyone help me by pointing me in the right direction when attempting this task
I think you mean independent assortment of homologous chromosomes and crossing over. Look at slides 5 and 3, respectively for each of these two processes in the attached file. Both lead to random "mixing" of genes and hence to variation - the third process [not asked for here] that leads to variation is random fertilization [meaning completely chance meeting of a particular sperm with a particular egg] and fourth is mutation.