ANATOMY

Detailed explanation-1: -The spindles start to attach to the Kinetochores of centromeres of sister chromatids during Prometaphase. The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down.

Detailed explanation-2: -During metaphase, the nuclear membrane disappears and the chromosomes become aligned half way between the centrioles. The centromere of each doubled chromosome becomes attached by thread-like spindle fibers to the centrioles which are at polar opposite sides of the cell.

Detailed explanation-3: -Nuclear membrane starts disappearing at the start of mitosis and by the late prophase it disappears completely along with the major cell organelles. The nuclear membrane disappears presumably to allow more space for karyokinesis and proper separation of chromatids.

Detailed explanation-4: -During telophase, a nuclear membrane forms around each set of chromosomes to separate the nuclear DNA from the cytoplasm.