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TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Biology > Cell Division - Mitosis

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Contents 1 State where cells arise from 2 Describe the cell cycle 3 Define interphase 4 Outline how replicated DNA molecules (chromosomes) are moved to opposite ends of the cell by microtubules 5 State the products of mitosis 6 State what tumours are the result of 7 Comments

State where cells arise from

All cells arise from the division of other cells.

Describe the cell cycle

The cell cycle is an alternation between interphase and mitosis.

Define interphase

Interphase is an active period in the life of a cell, where many biochemical reactions, DNA transcription, and DNA replication occur.

Outline how replicated DNA molecules (chromosomes) are moved to opposite ends of the cell by microtubules

In prophase the mitotic spindle forms.

In prometaphase the chromosomes attach to the mitotic spindle at the centromere.

In metaphase, the condensed chromosomes align in a plane across the equator of the mitotic spindle.

Anaphase follows as the separated chromatids move abruptly toward opposite spindle poles.

Finally, in telophase a new nuclear envelope forms around each set of unraveling chromatids.

The mitotic spindle is composed of microtubules, each of which is a tubular assembly of molecules of the protein tubulin.

Microtubules can grow or shrink by the addition or removal of tubulin molecules. This change in length propels attached chromatids to the spindle poles, where they unravel to form new nuclei.

State the products of mitosis

The products of mitosis are two genetically identical nuclei within the same cell.

State what tumours are the result of

Tumour are the result of uncontrolled cell division and that they can occur in any organ.

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