(a(i))[4]
Suggest how the closing of the eyelids during a sneeze is coordinated.
(a(ii))[2]
Suggest how sneezing can cause disease transmission.
(b(i))[2]
A rapid rise in light intensity may trigger sneezing in some people. This is known as photic sneezing. It is estimated that $18$-$35\%$ of the human population can be caused to sneeze by a rise in light intensity. The genetic basis of photic sneezing is not completely clear, but it is believed that a dominant allele is involved. Give the name of this type of variation in a population and explain your answer.
(b(ii))[2]
Describe what is meant by the term dominant allele.