m itotic p hase chapter 9.3. o bjectives summarize the major events that occur during each phase of...
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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.