In what phase does crossing over occur?

The many volcanoes located along the edge of the pacific ocean make up the ring of fire. how does subduction play a role in the volcanic activity in the ring of fire?

Prior to the development of dna fingerprinting, blood type could be used to determine possible parentage. although it might prove someone was not a parent, it could not show if someone was positively the parent, only that he or she might be a parent. which of the following is a true statement that can be made about parentage based on blood typing?

An easy way to calculate the amount of energy available at each level is to what?