Mitosis and Cytokinesis. During mitosis, when the nucleus divides, the two chromatids that make up each chromosome separate from each other and move to opposite poles of the cell. Mitosis actually occurs in four phases. The phases are called prophase, metaphase, anaphase, and telophase.
Keeping this in consideration, what phase is the spindle formed?
PROPHASE: During the prophase the nucleoli in the nucleus disappear. The chromatin fibers become tightly ccoiled and condense into chromosomes. Chromosomes line up in pairs and are joined at the centromere. In the cytoplasm, the spindle fibers begin to form and are made of microtubules.
What is the first phase of mitosis?
Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes — which were duplicated during S phase — condense and become thousands of times more compact than they were during interphase.