Cell division

• The nucleus of a cell contains chromosomes. Each chromosome carries a large number of genes made up of DNA molecules
• Chromosomes are made up of dna molecules
• each chromosome carries a large number of genes
• in normal body cells the chromosomes are normally found in pairs
• the nucleus of a cell contains chromosomes
• Body cells divide to form two identical daughter cells by going through a series of stages known as the cell cycle
• Cell division by mitosis is important for the growth and repair of cells, for example, the replacement of skin cells. Mitosis is also used for asexual reproduction
• a stem cell is a undifferentiated cell that can differentiate into one or more specialised cell types
• adult stem cells are stem cells from adults that can only differentiate into certain specialised cells
• where can adult stem cells be found?

  bone marrow
• Embryonic stem cells are stem cells from embryos that can differentiate into any specialised cell
• Where are embryonic stem cells found?

  early human embryos (usually from spare embryos from fertility clinics)
• Therapeutic cloning is patient’s cells are used to create an early embryo clone of themselves – stem cells from the embryo can then be used to treat patients medical conditions
• three main stages in the cell cycle

  A) bigger

  B) replicates

  C) ribosomes

  D) divides

  E) two

  
• what are plant meristems


  area where rapid cell division occurs in the tips of roots & shoots
• what is cell division by mitosis

  body cells divide to form two identical daughter cells
• what is purpose of mitosis


  growth and repair of cells, asexual reproduction
• the term for cell division in bacteria is called binary fission
• Cell division in bacteria is called binary fission. In optimum

  temperature and nutrients, bacteria can multiply as often

  as every 20 minutes. In a lab, bacteria can be grown in

  sterile conditions on an agar gel plate or in a nutrient broth.
• in binary fission the lid of the petri dish must be sealed but not all the

  way so that oxygen can still get in. This is so that harmful

  bacteria that do not need oxygen aren’t able to grow.

  
• There are two types of stem cell in mammals: adult stem cells and embryonic stem cells.
• Stem cells can be cloned to produce large numbers of identical cells.
• stem cells in medicine

  
• In therapeutic cloning:

  ● cells from a patient’s own body are used to create a cloned early embryo of themselves

  ● stem cells from this embryo can be used for medical treatments and growing new organs

  ● these stem cells have the same genes as the patient, so are less likely to be rejected

  when transplanted.