Mitosis

What are the stages of mitosis in order?

1. interphase

2. Prophase

3. Metaphase

4. Anaphase

5. telophase

6. Cytokineisis

What happens in interphase?

• DNA replication

• cell growth

• organelles replicate

• protein/ enzymes synthesised

How does the cell look during interphase?

What happens during prophase?

• chromosomes : condense, coil, shorten, thicken - becomes visible

• centrioles move to poles and spindles

• nuclear envelope disintegrates

How does the cell look during prophase?

What happens during metaphase?

• spindle fibre attaches to centromere

• chromosomes align on the equator

How does the cell look during metaphase?

What happens during anaphase?

• spindle fibres shorten - centromeres separate

• now separated chromatids pull to opposite poles by centromere

How does the cell look during anaphase ?

What happens during telophase?

• chromosomes uncoil and lengthen

• spindle fibres break down

• nuclear envelope reforms

• nucleolus reappears

How does the cell look during telophase?

What happens during cytokinesis?

• cytoplasm divide making 2 cells

What does haploid mean?

23 chromosomes in total [n]

What does diploid mean?

46 chromosomes in total [2n]

What does ploidy level mean?

number of complete sets of chromosomes in an organism

What does polyploid mean?

organisms with more than 2 complete sets of chromosomes

what does homologous mean?

matching pair of chromosomes

What are the uses of mitosis?

• growth

• asexual reproduction

• repair

How are the chromosome number affected in mitosis?

• same as parent cell

• exact replica - genetic stability

How is mitosis useful for growth?

• replace dead cells

• repair tissues - producing new cells

How is mitosis used in asexual reproduction?

• no genetic variation - unicellular organisms

What happens if genes are damaged?

• uncontrollable mitosis

• unaltered - proton-oncogenes

• altered - oncogenes (cancer)