Eukaryotic cells reproduce by mitosis, the process of nuclear division, and cytokinesis, the process of cytoplasm division.

Section 2: Mitosis and Cytokinesis

KWhat I Know

WWhat I Want to Find Out

LWhat I Learned

• 5(A) Describe the stages of the cell cycle, including deoxyribonucleic acid (DNA) replication and mitosis, and the importance of the cell cycle to the growth of organisms.

• 4(B) Investigate and explain cellular processes, including homeostasis, energy conversions, transport of molecules, and synthesis of new molecules.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Essential Questions• What are the events of each stage of mitosis?• What is the process of cytokinesis?

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Review• life cycle

New• prophase• sister chromatid• centromere• spindle apparatus• metaphase• anaphase• telophase

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Vocabulary

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Mitosis• During mitosis cell’s replicated genetic material separates and the

cell prepares to split into two cells.

• The key activity of mitosis is the accurate separation of the cell’s replicated DNA.

• Mitosis:

• Increases the number of cells in a multicellular organism as it grows

• Replaces damaged cells

Mitosis and CytokinesisCopyright © McGraw-Hill Education

The Stages of Mitosis (Mitosis Rap)

Prophase• Prophase is the first and longest stage of mitosis.

• Cell’s chromatin tightens/condenses into chromosomes.

• Sister chromatids are structures that contain identical copies of DNA.

• The sister chromatids are attached at the centromere.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

The Stages of Mitosis

Prophase• As prophase continues, spindle fibers, centrioles, and aster fibers

form a spindle apparatus.

• The spindle apparatus attaches to each of the sister chromatids before cell division.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

The Stages of Mitosis

Metaphase• The second stage of mitosis is metaphase – the shortest phase.

• Sister chromatids are pulled along the spindle apparatus toward the center of the cell.

• They line up in the middle of the cell.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

The Stages of Mitosis

Anaphase• During anaphase, the chromatids pull apart.

• The microtubules of the spindle apparatus begin to shorten.

• The sister chromatids separate.

• The chromosomes move toward the poles of the cell.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

The Stages of Mitosis

Telophase• Telophase is when the chromosomes arrive at the poles and begin

to decondense.

• Two new nuclear membranes begin to form and the nucleoli reappear.

• The spindle apparatus disassembles.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Cytokinesis• After the two daughter nuclei have formed, cells undergo cytokinesis.

• In animal cells, microfilaments constrict/pinch off to form two cells.

• In plant cells, instead of pinching in half, a new structure called the cell plate forms between the two daughter nuclei.

Visualizing the Cell Cycle

Animation

FPOAdd link to animation from page 249 (figure 6) here.

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Mitosis and CytokinesisCopyright © McGraw-Hill Education

Review

Essential Questions• What are the events of each stage of mitosis?• What is the process of cytokinesis?

Vocabulary

• prophase• sister chromatid• centromere

• spindle apparatus• metaphase

• anaphase• telophase