Specific details paper 2

• Cerebral cortex


  Responsible for consciousness, intelligence, memory and language
• Medulla


  Controls unconscious activities like breathing and heart rate
• Cerebellum


  Responsible for muscle co-ordination
• Sclera


  White, tough supporting wall of the eye, it is also a protective layer
• Optic nerve


  Transfers visual impulses from the receptors on the retina to the brain
• Cornea


  This is the transparent frontal part of the eye that is needed to refract light into the eye
• Iris 


  Controls the pupil diameter and the quantity of light reaching the retina
• Pupil


  A hole in the centre of the eye that allows light to pass through
• Ciliary muscles


  Ring of smooth muscle that changes the shape of the lens to focus light
• Suspensory ligaments 


  A ring of fibres that connect ciliary muscles to the lens
• Lens


  Focuses light onto the retina
• Explain how a person's eye could adjust to form a clear image of a nearer object

  ciliary muscles contract

  so ciliary muscles have a smaller diameter

  suspensory ligaments loosen / slacken

  lens thickens or lens becomes more curved / rounded (thicker)

  lens is more convergent

  light rays / image focused on retina
• Species order classification


  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• Selective Breeding


  Take one male and one female desired creature

  Breed the 2 to create an offspring with the desired genetic properties/characteristics

  Select the best offspring from each generation and repeat the breeding process
• Explain how a persons eye could be adjusted to view an object further away

  Ciliary muscles relax

  so the ciliary muscles have a larger diameter

  the suspensory ligaments tighten

  The lens becomes more flat

  The lens is more concave

  light rays focus towards the back of the retina
• Iris reflex


  In dim light

  radial muscles will contract

  circular muscles will relax

  pupil will get larger

  so more light can enter
• Iris reflex 2


  In bright light

  radial muscles will relax

  circular muscles will contract

  pupil gets smaller

  less light can enter