(a)[1]
Arrange the parts in the correct order. Two are already done for you.
(b)[3]
Describe how impulses pass from one neurone to another across the synapse.
(c(i))[2]
State two withdrawal symptoms that a heroin user may experience.
(c(ii))[1]
Suggest why heroin abuse may lead to more crime.
(d(i))[4]
Explain how vaccination stimulates active immunity.
(d(ii))[2]
Explain what is meant by passive immunity.