sister chromatids are introduced during the (S) or synthesis phase of cell division. The two sister chromatids are separated from each other into two different cells... O <--> O
during mitosis or during the second division of meiosis.
So no, they are apart of a phase, but aren't the entirety of cell division.
It is 1 amu.....................
Almost all skin cancers<span> </span><span>are </span>caused<span> by too much </span>UV radiation <span>from the sun or other sources such as solarium, tanning beds, and sun lamps. UVB penetrates into the epidermis </span>causing<span> damage to the cells.</span>