Biology Textbook P.214

Q.5

i )

ii ) light sensitive cells on retina are stimulated

   nerve impulse are set up

   and transmitted along optic nerve

   to the cerebral cortex for interpretation into vision

iii ) ciliary muscles contract

   suspensory ligaments loosen

   lens become more convex

iv ) Path of light rays from a nearby object after correction

Q.6

i ) ( 1 ) A, B

    ( 2 ) A – semicircular canals, detect direction of head movement

           B – cochlea, detect sound vibration

ii ) air pressure on 2 sides of eardrum become unequal

   ear drum was pressed outwards

   and could not vibrate freely

iii ) pathogens in throat

   have spread along the Eustachian tube to the middle ear