2.2.2 stem cells & cell differentiation

• in human adults, stem cells can be found in bone marrow as well as other tissues and organs
• adult stem cells can differentiate into fewer cell types than stem cells in embryos
• Stem cells are used to replace dying cells and damaged tissues
• The stem cells in embryos can differentiate into most cell types, to produce all of the cell types that will make up the organism
• Plant stem cells are found in the meristem tissue
• Plant stem cells can differentiate into all types of plant cell throughout the life of the plant. This allows plants to grow for their whole lives
• Stem cell locations:

  • P,M - plant meristems
  • B,M - bone marrow
  • E - embryos
• Embryos

  • cell differentiation happens during an organism's development
  • organisms start as one cell
  • these cells divide to form embryos that differentiate (specialise) to produce cells that can perform all of the body's functions
• Plants

  • many plant cells keep their ability to differentiate throughout their life
  • because of this, plants are always able to create new tissues (matter that animals and plants are made from)
• Adult animals

  • cell differentiation is rare in mature animals
  • their cells mostly divide in order to replace and repair tissues
  • new tissues are rarely created
• What happens when a cell differentiates?

  It becomes a different type of body cell
• Plant stem cells can be used for protecting rare plant species, improving food security, and producing crop plants with special features