Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called

Prior to mitosis, each chromosomes of a eukaryotic cell consists of a pair of identical structures called SISTER CHROMATIDS. It is the original chromosome of the cell that will divide into these two sister chromatids. The two sister chromatids will be separated from each other into two different cells during mitosis. 

The return of the wolf to yellowstone national park will probably affect the bird population to some degree, not significantly. while wolves will hunt birds when necessary, they prefer to hunt larger prey. the bird population will most likely only be affected when hunting is scarce for the wolves. birds of prey will also probably not be affected as much as other birds who spend more time on the ground hunting for food as the tend to spend more time in the air or in trees since they do not need to stay on the ground for long due to the nature of the way they hunt.