Cell division& chromosomes,mitosis and cell cycle,stem cells

• What do chromosomes contain in cells?


  Genetic material in the form of DNA
• What is the structure of chromosomes?


  Chromosomes are coiled lengths of DNA molecules
• What do different genes control in an organism?


  The development of different characteristics
• How many copies of each chromosome do body cells normally have?


  Two copies, one from each parent
• How many pairs of chromosomes do humans have?


  23 pairs of chromosomes
• What is the cell cycle and its significance in multicellular organisms?


  • Body cells divide to produce new cells
  • Mitosis is the process of cell division
  • Used for growth and replacing damaged cells
  • Results in two identical daughter cells with the same number of chromosomes
• What is the process called when a cell divides?

  Mitosis
• What happens at the end of the cell cycle?


  Two new cells identical to the original cell are produced
• What are embryonic stem cells capable of?


  They can turn into any type of cell
• What is differentiation in the context of stem cells?


  It is the process where a cell changes to become specialized for its job
• What is undifferentiation in stem cells?


  It refers to stem cells making more stem cells
• How can stem cells be used in medicine?


  • Replace faulty blood cells from healthy bone marrow
  • Replace faulty cells in sick people (e.g., insulin-producing cells for diabetes)
  • Therapeutic cloning to avoid rejection by the body
• What is therapeutic cloning?


  Creating an embryo with the same genetic information as the patient
• What is a risk associated with lab-grown stem cells?


  Risk of contamination with a virus
• What are some ethical concerns regarding stem cell research?


  • Human embryos have potential human life
  • Some countries have banned stem cell research
  • Embryos used are usually unwanted from fertility clinics
• How can stem cells be used in agriculture?


  • Produce identical plants from meristems
  • Create quick clones
  • Grow copies of rare species
  • Develop desired features like disease resistance
• What are the steps of mitosis?


  1. Contents and DNA are copied
  2. Chromosomes line up at the center
  3. Cell fibers pull chromosomes apart
  4. Membranes form around each set of chromosomes
  5. Cytoplasm and cell membrane divide
  6. Two identical daughter cells are produced
• What happens to the DNA in daughter cells after mitosis?


  The DNA is identical to the parent cell