Biology 7402: Organisms Exchange Substances With Their Environment Topical Past Paper Questions

$$ [25~\mathrm{m a r k s}] $$ [25 marks]

1 Chitin is a polysaccharide. The chitin monomer is a $\beta$-glucose molecule with one OH group replaced by an $\text{NHCOCH}_3$ group. $\text{NHCOCH}_3$ can be represented by N(Ac). Figure 1 shows the monomer that forms chitin and the chitin polymer. Figure 1 Chitin has a simil…

Figure 11 shows images of gills from two fish as seen through an optical microscope. Image C shows gills from a fish with healthy gills. Image D shows gills from a fish with damaged gills. Figure 11 not reproduced here due to third-party copyright restrictions 1) To observe the f…