Download 5.2 Mitosis and Cytokinesis

5.2 Mitosis and Cytokinesis
KEY CONCEPT
Cells divide during mitosis and cytokinesis.
5.2 Mitosis and Cytokinesis
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I can describe the structure of a chromosome.
• I can follow chromosomes through the processes of mitosis
and cytokinesis.
5.2 Mitosis and Cytokinesis
Chromosomes condense at the start of mitosis.
• DNA wraps around proteins (histones) that condense it.
DNA double
helix
DNA and
histones
Chromatin
Supercoiled
DNA
5.2 Mitosis and Cytokinesis
• DNA plus proteins is called chromatin.
chromatid
• One half of a duplicated
chromosome is a chromatid.
• Sister chromatids are held
together at the centromere.
• Telomeres protect DNA and do
not include genes.
telomere
centromere
telomere
Condensed, duplicated chromosome
5.2 Mitosis and Cytokinesis
Mitosis and cytokinesis produce two genetically identical
daughter cells.
Parent cell
• Interphase prepares
the cell to divide.
• During interphase,
the DNA is
duplicated.
centrioles
spindle fibers
centrosome
nucleus with
DNA
5.2 Mitosis and Cytokinesis
• Mitosis divides the cell’s nucleus in four phases.
– During prophase, chromosomes condense and
spindle fibers form.
5.2 Mitosis and Cytokinesis
• Mitosis divides the cell’s nucleus in four phases.
– During metaphase, chromosomes line up in the
middle of the cell.
5.2 Mitosis and Cytokinesis
• Mitosis divides the cell’s nucleus in four phases.
– During anaphase, sister chromatids separate to
opposite sides of the cell.
5.2 Mitosis and Cytokinesis
• Mitosis divides the cell’s nucleus in four phases.
– During telophase, the new nuclei form and
chromosomes begin to uncoil.
5.2 Mitosis and Cytokinesis
• Cytokinesis differs in animal and plant cells.
– In animal cells, the
membrane pinches
closed.
– In plant cells, a cell
plate forms.
5.2 Mitosis and Cytokinesis
The processes of mitosis and cytokinesis produce two
identical
• a. daughter cells.
• b. strands
• c. chromosomes.
• d. chromatids.
5.2 Mitosis and Cytokinesis
The process of organizing and condensing DNA into its
compact form takes place at the start of
• a. interphase.
• b. metaphase.
• c. mitosis.
• d. cytokinesis
5.2 Mitosis and Cytokinesis
Which is the term for the group of proteins that organizes
and condenses long strands of DNA into tight coils?
• a. telomeres
• b. centromeres
• c. chromatids
• d. histones
5.2 Mitosis and Cytokinesis
During which phase of mitosis do sister chromatids
separate from each other?
• a. prophase
• b. metaphase
• c. anaphase
• d. telophase
5.2 Mitosis and Cytokinesis
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Which of the following statements is true of cytokinesis?
a. takes place in plant cells only
b. completes the cell cycle
c. organizes DNA
d. occurs during prophase