MITOTIC PHASEChapter 9.3

OBJECTIVES

Summarize the major events that occur during each phase of mitosis.

Explain how cytokinesis differs in plant and animal cells.

VOCABULARY

spindle centrosome prophase metaphase anaphase telophase cell plate

MITOSIS DANCE

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.

INTERPHASE

Cell Makes new molecules and organelles In late interphase (G2), the DNA has been

duplicated. Chromosomes not visible, still loosely packed

PROPHASE

Chromatin has condensed into chromosomes Nuclear envelope breaks down Spindle fibers appear Microtubules from spindle attach to

chromatids Tugging begins

METAPHASE

Chromosomes line up across the middle of the cell.

Spindles move to the poles (ends) of the cell.

ANAPHASE

Sister chromatids are pulled apart by the spindle fibers.

Some spindles pull chromatids, others push the poles further apart.

TELOPHASE AND CYTOKINESIS

Telophase: chromosomes reach poles, spindle disappears, two nuclei reform, and chromosomes unwind back to chromatin

Cytokinesis: cytoplasm divides and cells pinch off and separate

CYTOKINESIS IN ANIMALS AND PLANTS

In animals, cytokinesis is a pinching of the cell.

In plants a cell plate is created to make a new cell wall.