MitosisDefine each of the following:

DNA:

Chromosome:

Mitosis:

Key terms: Key terms: mitosis, prophase, metaphase, anaphase, telophase

MitosisObjectives Outcomes

3: Describe how the cells produced by mitosis are genetically identical to the parent cells.

5: Explain in detail the stages involved in mitosis.

7: Link all stages of the cell cycle including mitosis in together to form an overall picture.

Key terms: Key terms: mitosis, prophase, metaphase, anaphase, telophase

Stages of mitosis

• Cell resting•Each chromosome is copied (DNA replication)

•Spindle forms. Chromosomes arranged along the equator•Chromosome single strands move to the poles of the cell•Two genetically identical cells are produced

Mitosis. Mitosis. What every cell knows is… it happens all the time.

Cells undergoing mitosis

Mitosis

Key terms: mitosis, prophase, metaphase, anaphase, telophase

Before a cell divides, its chromosomes are copied exactly in INTERPHASE. This process is called replication; ATP is synthesised – provides energy for cell division; organelles are replicated and proteins are made

PROPHASEThe DNA of each chromosome is copied to form two chromatids (“sister” chromosomes); chromosomes condense – becoming shorter and fatter – visible under LM; nuclear envelope breaks down; chromosomes lie freely in cytoplasm; centrioles move to opposite ends of the cell, forming protein (tubulin) fibres across it called a spindle – fibres extend to the equator of the cell

METAPHASEChromosomes line up at the equator; the spindle fibres from each pole become attached to the centromere of the chromosomes

ANAPHASEThe spindle fibres contract; the centromeres are split and the pairs of sister chromatids are separated and dragged to opposite poles assuming a “V” shape – the centromeres lead; a complete set of chromosomes is therefore found at each pole; energy (ATP) is required

TELOPHASEChromatids reach their respective poles and uncoil – become thin and long again – now called chromosomes again – no longer visible under LM; spindle fibres break down; nuclear envelope forms around each group of chromosomes – forming two nuclei; cytokinesis follows – cytoplasm divides and a plasma membrane forms two form two individual cells; cell enters interphase once again

Cytokinesis

Division of the cytoplasm (cytokinesis) into two equal parts follows mitosis

A “waist” forms in the middle of the cell. Eventually, the plasma membrane from one side of the cell joins that of the opposite side of the cell and the two new cells separate. The two daughter cells are genetically identical.

The equator of the cell is constricted by a ring of contractile proteins (actin) in the process of cleavage, to create two cells.

In plant cells, the Golgi apparatus and associated secretory vesicles assemble at the equator. Their contents are deposited to form a plate (the cell plate). Some vesicles remain intact and make connecting channels, termed plasmodesmata, through the new cell wall.

Prophase

Metaphase

Anaphase

Telophase

Mitosis

Key terms: mitosis, prophase, metaphase, anaphase, telophase

MitosisTasks

Complete the sheet on mitosis

Add details of mitosis to your cell cycle poster from last

lesson.

Outcomes3: Describe how the cells produced by mitosis are genetically identical to the parent cells.

5: Explain in detail the stages involved in mitosis.

7: Link all stages of the cell cycle including mitosis in together to form an overall picture.

Key terms: Key terms: mitosis, prophase, metaphase, anaphase, telophase

Mitosis

Key terms: mitosis, prophase, metaphase, anaphase, telophase

Mitosis

Key terms: mitosis, prophase, metaphase, anaphase, telophase

Reflection Pyramid1 question you still have

2 skills you have used.

3 things you have learnt

OutcomesGrade C: Describe how the cells produced by mitosis are genetically identical to the parent cells.

Grade B: Explain the stages involved in mitosis.

Grade A: Explain why plants retain the ability to grow throughout their lives whereas cell division in mature animals is involved in repair and replacement of tissues.