What are the different stages of Mitosis?

Mitosis occurs in a continuous, sequential order and has 5 stages:
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase. 
Interphase
Interphase occurs before Mitosis and is the process where the cell is preparing for division.
·         DNA replicates
o   Chromosome in nucleus consists of two connected copies called sister chromatids. Chromosomes are decondensed and long so cannot be seen.
·        Organelles replicate
o   There are two centrosomes for division.
·         More ATP is produced
o   ATP is used as an energy source for cell division.
 
1.       Prophase
Prophase is the first stage of mitosis.
·         Chromosomes condense
o   This makes them easier to pull apart
·         Centrioles move and spindles form
o   Centrioles move to opposite poles of the cell and begin to form spindles.
o   Spindles are protein fibres and are part of the cell’s ‘skeleton’. They organise the cells and move the chromosomes during mitosis.
·         Nuclear envelope breaks down
o   The nuclear envelope is the membrane of the nucleus.
o   It breaks down so that the chromosomes are free in the cell.
 
2.       Metaphase
·         Spindle fibres capture chromosomes on their centromere
o   Centromere is the part of DNA where the sister chromatids are tightly bound together.
o   The chromosomes are lined up the middle of the cell by the spindle fibres
·         Metaphase checkpoint
o   The cell checks that all the cells are attached to spindles and aligned in the centre of the cell.
 
3.       Anaphase
·         Sister Chromatids move to opposite sides of the cell
o   Spindle fibres contract and pull the chromatids apart, moving centromere first.
 
4.       Telophase
·         Chromatids reach opposite ends of the cell
o   Chromatids uncoil, lengthen, and are called chromosomes again.
·         Spindle fibres break down
·         Nuclear envelope starts to form around each group of chromosomes.
o   There are now two nuclei
Cytokinesis
Cytokinesis is the division of the cytoplasm to form 2 cells. It overlaps in mitosis, starting in anaphase and finishing in telophase.
·         Animal calls form a cleavage furrow which is a pinch crease to divide the cell membrane.
·         There are now two daughter cells which are genetically identical to the original cell.

Answered by Ellen C. Biology tutor

10526 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Describe the course taken by a deoxygenated red blood cell returning to the heart from the circulation, naming any vessels or chambers along its course.


Describe IVF


What is the second line of defence?


In what circumstances and how do humans anaerobically respire?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy