Bellwork

What are the stages of the cell cycle?Which stage is dna synthesized?Which stage is characterized by increase

in cytoplasm and organelles?Which stage includes cytokinesis?Which stage does the cell prepare to

undergo mitosis?

Chapter 5.2Mitosis and Cytokinesis

Objectives 5.2

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

Discuss how cytokinesis differs in plant and animal cells.

Prior to Mitosis 5.2Interphase has occurred and genetic material still in chromatin form.

Cells have◦ made more cytoplasm and organelles (G1)

◦Copied DNA (S)◦Made structures for cell division (G2)

Mitosis 5.2Split into 4 phases.ProphaseMetaphaseAnaphaseTelophase

Mitosis – Prophase 5.2

• Nuclear envelope breaks down.

• Chromatin fibers condense into chromosomes.

• Chromosomes are joined to make sister chromatids.

Mitosis – Prophase 5.2

• Mitotic spindle forms attaching microtubules to each chromatid.

• Chromosomes are pulled toward the middle of the cell.

Mitosis – Metaphase 5.2

Chromatids line in the middle of the cell attached to spindle microtubules.

Chromatids line up halfway between the two halves (poles) of the cell.

Mitosis – Anaphase 5.2• Sister chromatids split up from their partner.

• Each chromatid is now considered a daughter chromosome.

• Chromosome moves towards the poles of the spindle by moving up the microtubule while it shortens.

Mitosis – Telophase 5.2Chromosomes reach the poles of the cell.

Spindle disappears while nuclear envelopes reform around each set of daughter chromosomes.

Chromosomes uncoil forming chromatin.

Cytokinesis 5.2Completes cell division by splitting the cytoplasm into two daughter cells.

Usually occurs along with telophase.

In Summary 5.2•Eukaryotic cells reproduce by mitosis, the process of nuclear division and cytokinesis, the process of cytoplasm division.