stem and specialised cells

• Specialized cells


  Different types of cells that make up complex organisms like animals and plants
• Examples of specialized cells in animals

  • Sperm cells
  • Muscle cells
  • Nerve cells
• Examples of specialized cells in plants

  • Root hair cells
  • Phloem cells
  • Xylem cells
• Sperm cell


  • Has half the genetic material of a normal adult cell
  • Has a flagellum to swim
  • Is streamlined to swim
  • Has many mitochondria for energy
  • Has digestive enzymes to break into egg
• Specialized cells


  Have a specific role, shape, structure and organelle composition to fulfill that role
• Differentiation


  The process by which cells become specialized
• Differentiation


  1. Single cell (zygote) divides

  2. Cells remain identical at first

  3. Cells then undergo differentiation
• Stem cells


  Cells that can repeatedly divide by mitosis and differentiate into different types of specialized cells
• Stem cells


  Cells that can divide by mitosis to form more cells and can differentiate into specialized cells
• Stem cells


  • Can divide by mitosis to form more cells
  • Can differentiate into specialized cells
• Human life starts


  1. Sperm cell fertilizes egg cell

  2. Forms a single cell called a zygote

  3. Zygote divides by mitosis over and over again

  4. Forms a small group of cells called an embryo

  5. Embryonic stem cells can differentiate into any type of cell
• Embryonic stem cells


  Stem cells found in the embryo that can differentiate into any type of cell
• Adult stem cells


  Stem cells found in adults that can only differentiate into a narrow range of cells
• Adult stem cells


  • Stem cells found in bone marrow that can differentiate into different types of blood cells
• Plant stem cells


  Stem cells found in plant tissues called meristems that can differentiate into all the cells and tissues the plant needs
• Plant stem cells persist for the plant's entire life, unlike embryonic stem cells which disappear by the time we're fully developed
• adult stem cells are found in small numbers throughout the body, they only give rise to specific types of tissues
• embryonic stem cells are derived from the inner mass of an embryo, they have the potential to develop into any type of body tissue
• stem cell - undifferentiated cell that can divide to produce more stem cells or differentiate into other types of cells
• embryonic stem cells have the potential to develop into any type of tissue or organ
• stem cell therapy is used to treat diseases such as diabetes, heart disease, spinal cord injuries and cancer
• stem cells are used to treat diseases such as leukaemia and other blood disorders
• differentiation - process whereby a stem cell becomes a specialised cell with a particular structure and function
• stem cells are also being researched for use in treating conditions like diabetes, heart disease and spinal cord injuries
• specialised cell - mature cell that has lost its ability to divide but is adapted to carry out a specific task
• the use of stem cells has raised ethical concerns due to their origin from human embryos
• in stem cell therapy, adult or embryonic stem cells are injected into damaged areas of the body where they can replace dead or diseased cells with healthy ones
• cell division - process by which a parent cell divides to form two daughter cells
• embryonic stem cells are derived from the inner mass of an early stage embryo
• embryonic stem cells are pluripotent as they can form most types of adult tissue but not placental tissue
• embryonic stem cells are totipotent as they can form all types of tissue including placental tissue
• differentiation is when a stem cell becomes a specialised cell with a particular function