Answer:
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
Hope this helped :)
Answer:
The sex chromosomes, X and Y.
Explanation:
If it is sex linked, it is passed on when the parent donates their X or Y chromosome to their offspring. "Sex-linked" means that depending on the biological sex of the offspring, it may or may not carry the gene for the trait.
It's number four, i remember it in the lesson. FLVS right?