OCR - A-Level - Biology - Mitosis Cycle

Mitosis

Prophase

Metaphase

Anaphase

Telophase

Meiosis is this but doubled

Only happens if DNA has been replicated (gone through interphase)

Nuclear envelope breaks down

Chromosomes condense - visible in stain

Centrioles divide (4 centrioles, 2 to each pole of the cell)

Strands of DNA are chromatids

2 chromatids

=

1 chromosome

4 chromatids

=

pair of chromosomes

Spindles form between centrioles at poles

Meet in the Middle

Middle is called equator

Centromere joins to spindle fibres

Apart (separation)

Spindle fibres retract

Centromere splits

Sister chromatids pulled apart

Become chromosomes

Motor proteins pull chromatids (ATP)

Chromosomes unravel (long and thin)

Spindle fibres break down

Nuclear envelope reforms

Cytokinesis occurs

Cytoplasm separates (pinched off)

Two genetically identical daughter cells made