State the name of the process that describes what happens to light as it moves from air into the cornea.
Describe and explain the changes that happen in the eye when the focus shifts from a far object to a near one.
Describe what rods and cones do in the eye.
Complete Table 3.1 to show how rods and cones are distributed across the retina. Choose from these words to finish the table; each word may be used once, more than once, or not used at all: many, few, none.
Colour blindness is sex-linked. State the evidence in Fig. 3.3 that supports this idea.
State the genotype of person 5. Use X and Y for the sex chromosomes and A for the dominant allele and a for the recessive allele in the colour blindness gene.
Use the information in Fig. 3.3 to finish the genetic diagram showing the chance of person 3 and person 4 having another child with colour blindness.