Graph 1 shows the range of light wavelengths detected by the three types of cone cells in normal colour vision. Graph 2 shows the range of light wavelengths detected by a person with one form of colour blindness. Each line shows a different type of cone cell.

Deduce, with a reason, the difference in colour perception between people with normal colour vision and those with this type of colour blindness.

Explain how sounds of different wavelengths are distinguished by the ear.

difference in colour perception:

a. cannot distinguish red and green 

reason:

b. green and red cones detect very similar wavelengths
OR
peak of altered green shifts to the right
OR
range of altered green wider «than normal green»

a. «movement of eardrum and ossicles» causes vibration of cochlear fluid 

b. hair cells in different position «along the basal membrane» have hair/cilia of different length  OWTTE

c. different hair/cilia vibrate at different wavelengths 

d. «different hair cells send different» nerve signals in the auditory nerve