Question – How are the processes of Mitosis, Cell Differentiation and Specialisation and Gene Function important to health?

mitosis1.gif Mitosis

  • -When cells are damaged, they are replaced by healthy cells that produced through Mitosis.
  • Mitosis is the process of cell division, and part of the cell cycle.

o It is comprised of 4 stages: prophase, metaphase, anaphase, and telophase, which is then followed by the continuation of the cell cycle, through cytokinesis.
  • -When cells are reproduced they replicate their parent cell, therefore must have the same set of genes activated, which in turn will ensure that they perform the same function.

  • For a general overview, please refer to the video and picture (left) for visual aid

http://www.youtube.com/watch?v=VlN7K1-9QB0&feature=related









Gene Function zygote.jpg


Genes – Hereditary units consisting of short sequences of DNA that determine a particular characteristic in an organism.

  • Genes control characteristics by directly or indirectly controlling the production of all the functional & structural compounds in living cells.
  • Every Multicellular organism starts out as a Zygote (fertilised egg) – a single cell. (pictured right)
  • Half of the zygote’s genes are donated by each parent.
  • Through the process of Mitosis, the Zygote divides to form a ball of cells – this is under genetic control; some genes “switch on” Mitosis, whilst other switch it “off.”
  • The growth & healing of tissues are dependent on protein metabolism, which is controlled by genes. Protein Metabolism refers to the various processes that synthesise and breakdown proteins and amino acids in tissues.

CelCell_Differentiation.jpgl Differentiation

  • -When the ball of cells reaches a particular size, cells begin to differentiate into various cells, such as nerve cells, muscle cells and epithelial cells [these cells make up a thin layer of tissue that covers organs, glands and other structures within the body]. (pictured left)

  • -Differentiation allocates specific functions to specific groups of cells and tissues, ensuring that the numerous, complex functions of an organism can be performed.

  • -For example, Muscle cells require proteins called Myosin and Actin, whilst other cells don’t require these proteins.

  • -During differentiation only the genes required for the functioning of the specialised cell will be “switched on.” For example, the genes for producing Actin & Myosin are “switched on” only in muscle cells.


Cell specialisation


  • -Cell Specialisation allows cells to develop the structure that best performs a specific function/s.

  • -In some cases, cells may become specialised to help prevent the entry of pathogens or to respond quickly when infectious agents are present.

  • -Diseases such as Diabetes and Rheumatoid Arthritis may develop as a result of the malfunctioning of specialised cell.





grazed_knee.jpg

So how do these processes all relate to health?


  • The degree to which an organism can maintain health depends on whether the cells are functioning properly and how well the body can repair an imbalance or malfunction.
  • When there is an injury, when cells are not healthy, or damaged, specialised cells will replace their own kind through mitosis at the site.
  • For example, if I graze my knee, the cells around the injured site will divide (mitosis) to replace the damaged cells.
  • For a person to maintain a state of health, genes need to be expressed, [that is, information from the genes are used to produce proteins, or simply expressed = "switched on"] to manufacture the several compounds the body requires.
  • Mitosis, genes and differentiation are crucial to the healthy growth of an organism from conception to adulthood. Even though differentiation and major growth occur only once, cells regularly reproduce to maintain the health of an organism.
  • There are negative effects of a gene malfunctioning to health. For example, if a gene malfunctions, and causes the process of Mitosis to distort, cell division may uncontrollably divide and form a tumour, which may lead to Cancer.
  • Similarly, a mutation of genes can result in disease. For example, Cystic Fibrosis results from genes that produce faulty enzymes.