Stem cells and cell division

• What is cell potency?

  The abiltiy for stem cells to differentiate into specilased cell types. It can be totipotent, pluripotent and multipotent.
• Explain embryonic stem cells>A embryo develops from a fertilised egg. if the cells are removed the embryo, they will differentiate into any of the 216 cell types. As the embryo develops into a multicellular body, the cells become highly differentiated.
• What is a blastocyst?

  It's a hallow ball of cells with a inner cell mass of about 50 cells. They are pluripotent stem cells.
• Explain adult stem cells?

  Adult stem cells are located in certain locations such as the bone marrow, brain, liver and skin. Adult stem cells are multipotent,.
• What is haploid?

  Cellls or organisms in which the nucei contains one copy of each chromosome
• What is homologous chromosome?

  Similar chromosomes.
• What is diploid?

  Cells or organisms in which the nuclei contains two copies of each chromosome
• In interphase, explain gap 1 phase (G1)?

  The cells grows bigger and will allow synthesis of new organelles.
• In interphase, what happens in DNA synthesis (S)?

  The cells replicate it's DNA ready to divide by mitosis. During DNA replication, each chromosome is copied sio that there are 2 identical strands.
• In interphase, what happens in gap 2 phase (G2)?

  During this phase, the cells keeps growing and cells prepare genetic material for mitosis by supercoiling DNA to form chromosomes.
• Why is mitosis important in the human body?

  It enables the growth of one fertilised cell into a multicellular organism. This ensures that all the cells in a multicellular organism has the same genetic information.
• In meiosis, explain genetic variation?

  Only one chromosome from each homologous pair ends up in each gamete . This is because the original parent chromosomes are distributed into the gametes.