Topic 2 - cells and control

• What is Mitosis?

  A cell division process that produces 2 genetically identical cells.
• Mitosis occurs when the cell needs to divide into two daughter cells, which are genetically identical copies of the parent cell
• What is Mitosis used for?

  Growth and repair.
• What are the stages of Mitosis?

  Interphase - Prophase - Metaphase - Anaphase - telophase - cytokinesis.
• During Mitosis, what happens during the Interphase?


  The DNA in the nucleus identically copies itself to form x-shaped chromosomes.
• During Mitosis, what happens during the Prophase?


  Chromosomes condense and the nuclear membrane breaks down.
• During Mitosis, what happens during the Metaphase?


  Chromosomes align at the center of the cell.
• During Mitosis, what happens during the Anaphase?


  Chromosomes separate and move towards opposite poles of the cell through spindle fibres.
• During Mitosis, what happens during the Telophase?


  membranes form around each set of chromosomes as they are ready to split up.
• During Mitosis, what happens during Cytokinesis?


  The cell membranes divide to form 2 separate but identical cells.
• The cells created by Mitosis are Diploid.
• Cancer is uncontrolled cell division and growth creating a mass of abnormal cells. This creates a tumor that damages surrounding tissue.
• What is cell differentiation?


  Cell differentiation is the process by which cells become specialized in structure and function.
• What is cell elongation?


  Cell elongation is the process by which a cell(in a plant) increases in length.
• Why is cell differentiation important?


  it allows cells to specialize and perform specific functions in an organism.
• In a percentile chart:

  • If a baby is on the 25th percentile for mass, it means that they are lighter than 75% of children their age and heavier than 25% of children their age

  
• What is an embryonic stem cell?


  An embryonic stem cell is a type of cell that can differentiate into any type of cell in the body and has the potential to regenerate damaged tissues and organs.
• What is an adult stem cell?


  A stem cell that can differentiate into most cell types and is found in adult tissues.
• What are meristem cells?


  Undifferentiated plant cells capable of continuous division and giving rise to various specialized cells.
• Where are embryonic stem cells found?


  Early human Embryos.
• Where are adult stem cells found?


  Bone marrow
• where are meristems found?


  In plants.
• What is the function of adult stem cells?


  Regeneration and repair.
• What is the function of embryonic stem cells?


  To differentiate into various cell types and tissues in the body.
• What is the function of meristem cells?


  Growth and development.
• What are the medical risks of using stem cells?


  Tumor development

  Rejection

  Disease transmission
• The Brain and the Spinal cord make up the central nervous system.
• What is the function of the cerebrum?


  Higher cognitive functions, such as thinking, memory, and perception.
• What is the function of the Cerebellum?


  Coordination and balance.
• What is the function of the Medulla Oblongata?


  Controls unconscious activities like breathing.
• How does a CT scanner work for scanning the brain?


  It produces X-rays that show the main part of the brain. It can show the damaged or diseased part which would help doctors with diagnosis.
• How does a PET scanner work for scanning the brain?



  They use radioactive chemicals that show parts where the brain is active.

  They can show the structure and function in real-time.

  It is good for studying disorders.
• It is hard to repair damage dealt to the CNS as it could cause permanent damage - making it hard to do surgeries.
• It is hard to access parts of the brain during surgery.
• What makes up the Nervous system?


  Brain, spinal cord, and nerves.
• What are the 3 types of neurons?


  Sensory, motor, and relay neurons.
• How does the central nervous system coordinate a response?


  1. Stimulus: External signal detected by sensory receptors.
  2. Sensory Neurons: Signal travels to the CNS along sensory neurons.
  3. CNS (Brain or Spinal Cord): Impulse reaches the CNS for processing.
  4. Processing in CNS: The brain determines the response; the spinal cord coordinates rapid reflexes.
  5. Motor Neurons: Response signal transmitted away from the CNS.
  6. Effector (Muscle or Gland): Effectors carry out the response (muscle contraction or gland secretion).
  7. Response: The effector responds to the original external stimulus.
• What are the adaptations of a sensory neuron?


  Long dendron - short axon - connected to receptor cells.
• What are the adaptations of a motor neuron?


  Contains a lot of dendrites - myelin sheath around the axon - connected to effector cells.
• What are the adaptations of a Relay neuron?


  Many dendrons and short dendrites - contain many branches of dendrons.