Can you please explain to me the difference between mitosis and meiosis? Thank you

  • 1 vote

Could you please help be I have the exam tomorrow and I need to know the difference clearly

Posted Wed 18th May, 2011 @ 17:14 by Beverley
Edited by Beverley on Wed 18th May, 2011 @ 17:14

3 Answers

  • 1 vote

Mitosis makes new cells for growth and repair, whilst meiosis is the making of gametes.

Mitosis creates two identical offspring, which have the same chromosomes as the parent cell, but meiosis creates four gametes all of which have half the usual number of chromosomes- this is so after fertilization you end up with the right amount of chromosomes (half from each parent).

Other differences are that in mitosis there is only one division and there is no variation- it is a form of asexual reproduction, but in meiosis there are two divisions and there is variation.

Hope this helps, it might be clearer on bitesize so you might want to check there for a better explanation. Good luck! x 

Answered Wed 18th May, 2011 @ 17:30 by Fatima
  • 0 votes

Mitosis is the division of somatic cells (body cells) - for growth and repair and Asexual reproduction. There's six stages in total: 

  1. interphase - replication of all cell content 
  2. prophase - chromosomes condense, centrioles start moving to opposite ends of the cell, forming foundations for the spindle fibres
  3. metaphase - chromosomes line up along the middle of the cell, attaching to the spindle by centromeres 
  4. Anaphase - centromeres divide pulling chromatids apart 
  5. Telophase - chromatids reach opposite poles on spindle, uncoil and become chromosomes again, nuclear envelope forms (now 2 nuclei) and the cytoplasm begins to divide 
  6. Cytokenisis - mitosis is finshed and each daughter cell, genetically identical, starts the interphase part again

Meiosis is the production of gametes (sex cells) so the sperm and the egg of humans. 

In meiosis the DNA replicates, so there are two identical copies of each chromosome, called chromatids. The DNA condenses to form double-armed chromosomes. The chromosomes arrange themselves into homologous pairs - pairs of matching chromosomes. 

  1. First division - the homologous pairs are separated, halving the chromosome number
  2. Second division - the pairs of sister chromatids (those formed in DNA replication) are separated
  3. Four new cells that are genetically different from eachother are produced because the pairs cross over during the 1st division! 

Hope this helps 

Answered Wed 18th May, 2011 @ 17:30 by Jordanna Wetenhall
  • 0 votes

Mitosis and meiosis are two ways that cells reproduce.

By mitosis a cell splits to create two identical copies of the original cell.

In meiosis cells split to form new cells with half the usual number of chromosomes, to produce gametes for sexual reproduction.

Mitosis:

Mitosis is a type of cell division. Mitosis occurs wherever more cells are needed. It produces two new cells that are identical to each other, and to the parent cell. The process of growth and division is called the cell cycle.

MITOSIS ONLY HAPPENS IN DIPLOID CELLS (DIPLOID = 46 CHROMOSOMES)

The cycle starts as the number of organelles - the different parts of the cell - increases. This is to ensure that each of the two new cells receives copies of all the organelles.

Picture guide: http://www.bbc.co.uk/schools/gcsebitesize/science/images/add_ocr_bimitosisa.gif

Meiosis:

Meiosis is a different kind of cell division. It is used to produce male and female gametes. A human body cell contains 46 chromosomes arranged in 23 pairs. The gametes are sperm or eggs, and only contain half as many chromosomes (23). This is why meiosis is sometimes called reduction division.

MEIOSIS ONLY HAPPENS IN HAPLOID CELLS (HAPLOID = 32 CHROMOSOMES, a good way to remember this is by remembering the 'H' in 'Haploid'. H standing for HALF)

Picture guide:http://www.bbc.co.uk/schools/gcsebitesize/science/images/aqaaddsci_13.gif

Answered Wed 18th May, 2011 @ 17:38 by Al