Biology

• What does the retina contain?

  rod and cone cells
• What does the pupil do?

  The pupil regulates the amount of light entering the eye.
• What does the cornea do?

  The cornea is the transparent outer layer of the eye that helps to focus light onto the retina.
• What does the lens do?

  Focuses
• What do the ciliary muscles do?

  Change the shape of the lens in the eye.
• What does the iris do?

  Controls the size of the pupil and regulates the amount of light entering the eye.
• To see something far away what shape is the lens?

  long and thin
• To see something close what shape is the lens?

  short and fat
• Why are Some people short sighted(can’t see distances)?

  eyeball is too long so light doesnt reach retina
• Why are some people long sighted(can’t see close)?

  eyeball is too short so light goes past retina
• How to you fix short sightedness?

  use a diverging lens
• How do you fix longsightedness?

  use a converging lens
• How does a diverging lens work?

  Diverging lens spreads out light rays.
• How does a converging lens work?

  bends rays of light
• What is catarax caused by?

  built up protein in lens
• What is colourblindness caused by?

  Defective or absent cones in the retina.
• What does a ct scan do?

  x ray beams move in circles, detectors measures absorption. Computer uses this to build images in layers

  denser parts are lighter
• What do PET scans do?

  patient is injected with radioactive glucose What releases gamma rays

  more active cells take in glucose and shows up red

  less active is blue
• What is cancer?

  Cancer is a disease characterized by the uncontrolled growth of cells in the body.