Mitosis

Mitosis

1. MITOSIS = asexual reproduction in eukaryotes

2. homologous chromosome = chromosome pairs, 1 from each parent, similar in length, gene position and centromere location, can have different alleles

3. PLOIDY -the number of sets of chromosomes in the nucleus of a biological cell

4. haploid number (n) is the number of chromosomes in a complete set - 23 in humans(gametes - meiosis)

5. diploid number (2n) is two complete sets of chromosomes - 46 in humans (somatic cells - mitosis)

6. G2 - loosely coiled replicated chromosomes

7. PROPHASE - occupies over half of mitosis, nuclear membrane breaks down & forms small vesicles & nucleus disintegrates, chromosomes condense into compact structures, each replicated chromosome seen as sister chromatids held by centromere

8. PROMETAPHASE - chromosomes migrate to middle of cell (known as metaphase plate), chromosomes continue to condense

9. METAPHASE - chromosomes align along metaphase plate of spindle apparatus

10. ANAPHASE - shortest time of mitosis, centromeres divide & sister chromatids are pulled apart & move to opposite ends of cell, separated sister chromatids become daughter chromosomes

11. TELOPHASE - nuclear membrane reforms around chromosomes grouped at either pole of cell, chromosomes uncoil & spindle fibres disappear

12. CYTOKINESIS - final cellular division to from 2 new cells, plants - cell plate forms along line of metaphase plate, animals - constriction of cytoplasm

13. MITOSIS - occupies a short amount of time, most of time is spent in interphase

14. CYTOKINESIS - division of cytoplasm to form 2 daughter cells, ensures diploid (2n) chromosome number is maintained

15. G0 - cell cycle arrest

16. G1 - 1st growth phase, cellular contents excluding the chromosome are duplicated

17. S - synthesis phase (DNA replication), each of the 46 chromosomes are duplicated by cell

18. G2 - 2nd growth phase, cell 'double checks' duplicated chromosomes for error & makes any needed repairs