cells and division

• what is the function of a nucleus?

  contains genetic information which come in the form of chromosomes and contain dna
• What is a gene?

  a small section of DNA that codes for protein and controls certain characteristics
• What are diploid cells?

  cells that have two sets of chromosomes
• what is a haploid cell?

  cells that only contains one set of chromosomes
• why is mitosis important?

  growth and development when repairing damaged cells

  
  

  asexual reproduction as it uses only one cell to reproduce
• what are the stages of mitosis?

  prophase - nuclear membrane starts to break down which free the chromosomes so the cytoplasm

  
  

  metaphase - chromosomes line up at the equator of the cell

  
  

  anaphase - spindle fibres pull chromosomes to opposite sides of the cell

  
  

  telophase - reach opposite sides of the cell and become chromosomes which form two nuclei

  
  

  cytokinesis - they divide and produce two genetically identical daughter cells
• what is cell differentiation?

  when a cell changes its shape or structure to become specialised
• what are the positives of stem cells?

  they divide by mitosis to form more cells

  
  

  they can differentiate into many different cells
• how are stem cells used in medicine?

  they extract embryonic stem cells from early embryos and stimulate them to differentiate so that they can replace faulty cells
• What are the drawbacks of embryonic stem cells?

  . theres a limited supply

  
  

  . there are ethical concerns
• what are the adv and dv of adult stem cells?

  adv - they wont lead to rejection by the patients body as it comes from the patients body

  
  

  dv - it can only differentiate into different types of blood cells