Topic 2 - Cells and Control

• What are chromosomes


  Chromosomes are long, thin strings of genetic material made of DNA and proteins.
• are cells produced by mitosis genetically identical or different?


  genetically identical
• What is mitosis used for?


  To grow or replace cells that have been damaged
• What are the stages of mitosis?


  prophase, metaphase, anaphase, telophase
• What is prophase


  The chromosomes condense, getting shorter and fatter. The membrane around the nucleus breaks down and the chromosomes lie free in the cytoplasm.
• What is metaphase

  Chromosomes line up in the middle of the cell
• What is anaphase


  Spindle fibres pull the chromosomes apart. Then the chromatids are pulled to opposite ends of the cell
• What is telophase


  Membranes form around each of the sets of the chromosomes. These become the nuclei of the two new cells- the nucleus has divided
• What is cytokinesis?


  division of the cytoplasm
• number of cells produced by mitosis=


  2^n (where n is the number of divisions by mitosis)
• What is growth?


  increase in size or mass
• What is cell differentiation?


  The process by which a cell changes to become specialised for its job
• What is cell elongation?


  Where a plant cell expands, making the cell bigger and so making the plant grow.
• What does all growth in animals happen by?

  cell division
• what is cancer?


  uncontrolled cell division
• What are stem cells?


  undifferentiated cells
• Where are adult stem cells found?


  In some organs and tissues e.g bone marrow
• Where are stem cells located in plants?


  meristems
• What diseases can be treated with stem cells?


  -sickle cell anaemia
• What is one benefit of stem cells in medicine?


  They can cure some diseases, such as sickle cell anaemia.
• How can stem cells be used to treat damaged tissues?


  They can create cells to replace those damaged by disease or injury.
• What type of cells can be transplanted into someone with heart disease?

  Cardiac muscle cells created from stem cells.
• What are the risks of a stem cells


  -tumour developent

  -disease transmission

  -rejection
• what are the ethical issues of embryonic stem cells?


  some people argue that human embryos shouldn't be used for experiments because each one is a potential human life.
• What is the spinal cord made up of?


  a long column of neurones that run from the base of the brain down to the spine
• What does the spinal cord do?


  Relays information between the brain and the rest of the body
• the brain is made up of billions of...

  interconnected neurones
• Where is the cerebrum

  
• what is the function of the cerebrum


  movement, intelligence, language, memory, vision

  (mum i love my violin)
• Where is the cerebellum

  
• What is the function of the cerebellum?


  muscle coordination and balance
• Where is the medulla oblongata

  
• What is the function of the medulla oblongata?


  Controls unconscious activities like breathing and heart rate
• How does a CT scanner produce an image of the brain


  using x rays
• what does a CT scanner show?


  Main structures of the brain, but not their functions
• What do PET scanners use?


  radioactive chemicals
• What do PET scanners show?


  how active different areas of the brain are
• what are the advantages of PET scanners?


  -very detailed and can be used to investigate both the structure and the function of the brain in real-time

  -can show if areas in the brain are unusually active or inactive, so they are useful for studying disorders that change brain activity
• Why is it difficult to treat problems in the CNS


  - hard to repair damage

  -not easy to access

  -risk that spinal cord could be damaged further , leading to permanent damage
• What are sensory receptors?


  Groups of cells that can detect a change in your environment (a stimulus)