In people infected with HIV, using ART also reduces the chance of the virus being passed on to uninfected people. Outline two control methods, other than ART, that can be used to reduce the transmission of HIV.
Define magnification
Research into the structure of \textit{P. jirovecii} has shown that its cell wall is composed of polysaccharides including chitin and $1,3$-$\beta$-D-glucan. Explain why this discovery enabled scientists to confirm that \textit{P. jirovecii} is not a bacterium.
Scientists have identified additional structural features of the cell of \textit{P. jirovecii}. Some of these are shown in Table 2.1. Complete each row of Table 2.1 so that the table includes: • four structural features identified in \textit{P. jirovecii} • one function for each structural feature • whether each structural feature is present ($\checkmark$) or absent ($\times$) in bacterial cells.
Cell-surface glycoproteins called gpA glycoproteins are vital for allowing \textit{P. jirovecii} cells to attach to alveolar epithelial cells and ECM proteins. Suggest how a gpA glycoprotein is able to attach to alveolar epithelial cells and ECM proteins.
A consequence of pneumonia caused by \textit{P. jirovecii} infection is a fall in the amount of oxygen delivered to body tissues. Explain why a severe \textit{P. jirovecii} infection results in a decrease in the quantity of oxygen that is delivered to body tissues.
\textit{P. jirovecii} makes an enzyme called $1,3$-$\beta$-D-glucan synthase. This enzyme catalyses the synthesis of $1,3$-$\beta$-D-glucan. The therapeutic drug caspofungin is a non-competitive inhibitor of $1,3$-$\beta$-D-glucan synthase. Referring to how caspofungin works, explain how the drug may be useful for treating pneumonia caused by \textit{P. jirovecii}.