"during which phase of mitosis does the nuclear membrane dissolve completely and the chromatid pairs arrange themselves in a single file? "

The answer is metaphase. It is marked by the arrangement of chromosomes at the center of the cell, half way between each of the mitoic spindle poles. Movement is intermediated by the kinetochore microtubles, which push and pull on the chromosomes to align them into what is called the metaphase plate. The chromosomes on the metaphase plate are held there firmly by pushing and pulling forces from the microtubules. Cells can stop in metaphase for days until the chromosomes are properly aligned and the cell go in anaphase.

each of the 46 original chromosomes splits into two daughter chromosomes, so there are two sets of 46 daughter chromosomes that end up in each cell. human cells have 46 chromosomes. each chromosome consists of a pair of identical chromatids attached together by a structure called a centromere.

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation: