M ITOTIC P HASE Chapter 9.3

O BJECTIVES Summarize the major events that occur during each phase of mitosis. Explain how cytokinesis differs in plant and animal cells.

V OCABULARY spindle centrosome prophase metaphase anaphase telophase cell plate

M ITOSIS D ANCE

During mitosis the chromosomes are controlled by tubes that stretch into a football shape. This framework is called the spindle. The tubes grow out of centrosomes and move the chromosomes around.

I NTERPHASE Cell Makes new molecules and organelles In late interphase (G2), the DNA has been duplicated. Chromosomes not visible, still loosely packed

P ROPHASE Chromatin has condensed into chromosomes Nuclear envelope breaks down Spindle fibers appear Microtubules from spindle attach to chromatids Tugging begins

M ETAPHASE Chromosomes line up across the middle of the cell. Spindles move to the poles (ends) of the cell.

A NAPHASE Sister chromatids are pulled apart by the spindle fibers. Some spindles pull chromatids, others push the poles further apart.

T ELOPHASE AND C YTOKINESIS Telophase : chromosomes reach poles, spindle disappears, two nuclei reform, and chromosomes unwind back to chromatin Cytokinesis : cytoplasm divides and cells pinch off and separate

C YTOKINESIS IN A NIMALS AND PLANTS

In animals, cytokinesis is a pinching of the cell. In plants a cell plate is created to make a new cell wall.