Mitosis and Meiosis
- Created by: farahh24
- Created on: 12-09-18 20:24
View mindmap
- Mitosis and Meiosis
- Mitosis
- Repair, replacement and growth. Produces two genetically identical daughter cells.
- Growth 1: Cellular contents duplicated
- Cell Cycle
- Synthesis: Chromosomes duplicated
- Growth 2: Checks duplicated chromosomes for error and makes repairs.
- Mitosis: Division of nucleus
- Cytokinesis: Division of cytoplasm.
- Mitosis: Division of nucleus
- Growth 2: Checks duplicated chromosomes for error and makes repairs.
- 1. Prophase:
- Nuclear envelope disintegrates.
- 3. Anaphase:
- Chromatids pulled to opposite poles.
- Spindle fibres contract.
- Chromatids pulled to opposite poles.
- 4. Telophase.
- Forms nuclear envelope.
- Chromatids have reached poles, now called chromosomes
- Forms nuclear envelope.
- Cleavage furrow forms at middle of cell.
- Plasma membrane pulled close enough to fuse around middle.
- Cytokenisis in animals
- Meiosis
- Cytokinesis in planes
- Vesicles from Golgi apparatus assemble at metaphase plate
- New sections of cell wall form along new sections of membrane
- Membrane must be formed before cell wall, or cell wall would undergo osmosis lysis.
- New sections of cell wall form along new sections of membrane
- Vesicles from Golgi apparatus assemble at metaphase plate
- Results in four daughter gametes with half the number of chromosomes
- Prophase 1:
- Chromosomes condense, nuclear envelope disintegrates.
- Homologous chromosomes form bivalents
- Crossing over: chromatids entangle, breaks off at chiasmata, genetic variation
- Homologous chromosomes form bivalents
- Chromosomes condense, nuclear envelope disintegrates.
- Metaphase 1:
- Spindle fibres attach to centromeres, homologous pairs line up at metaphase plate
- Orientation of pairs to either pole is random - independent assortment.
- Spindle fibres attach to centromeres, homologous pairs line up at metaphase plate
- Grey= genetic variation
- Anaphase 1:
- Homologous pairs pulled to either pole.
- Telephase 1:
- Chromosomes assemble at opposite poles, nuclear membrane forms.
- Prophase 2:
- Chromosomes condense.
- Nuclear envelope disintegrates.
- Centrioles at opposite poles.
- Nuclear envelope disintegrates.
- Chromosomes condense.
- Metaphase 2:
- Chromosomes line up at equator.
- Independent assortment - orientation of chromosomes to either pole is random
- Chromosomes line up at equator.
- Anaphase 2:
- Chromotids of chromosomes pulled to either pole of cell.
- Telophase 2:
- Chromatids assemble at poles.
- Nuclear envelope formed.
- Chromatids assemble at poles.
Comments
No comments have yet been made