The genetic material of Morbillivirus is a strand of RNA. Statements A, B and C refer to RNA structure. State the correct term or terms for statements A to C. A: The names of the two purines and two pyrimidines found in RNA. B: The type of covalent bond joining RNA nucleotides. C: The pentose sugar present in an RNA nucleotide.
Describe the transmission of measles.
Young children who have measles can develop breathing problems. These become more severe if the child is repeatedly exposed to tobacco smoke. Tobacco smoke includes harmful substances such as carbon monoxide.
Inhaled tobacco smoke moves through the larynx (voice box) and the other parts of the gas exchange system before reaching the alveoli. Complete Fig. 5.1 by listing, in the correct order, the main structures of the gas exchange system through which tobacco smoke passes on its way to the alveoli.
State the short-term effects produced by carbon monoxide on the cardiovascular system.
Smallpox is a disease that was eradicated with the aid of a global vaccination programme. Measles has not been eradicated, despite the existence of a global vaccination programme. Fig. 5.2 is a graph that shows estimates of the number of deaths from measles worldwide, between 2000 and 2017, for people who have not been vaccinated.
State the trend in Fig. 5.2 from 2000 to 2017.
Suggest reasons for the trend seen in Fig. 5.2.
A child with leukaemia has a high risk of developing measles even though the child has a high white blood cell count and has been vaccinated against the disease. Explain why this child is at high risk of developing measles.