Which animals have hair

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

Northern switzerland has a fairly cold climate caused by sea winds from the atlantic ocean but souther switzerland tends to be much warmer and sunnier, what could cause this difference?

We all have different forms of genes from our parent(s).what are these different forms called? a.alleles b.characters c.dna d.resources