Lichens occur on trees, walls, rocks and soil. Fig. 9.1 shows a lichen belonging to the genus Usnea. Usnea withstands only low concentrations of sulfur dioxide and cannot grow where the air is polluted with sulfur dioxide. Usnea is made up of a mixture of two cell types: photosynthetic cells, which are placed in the kingdom Protoctista, and fungal cells, which are placed in the kingdom Fungi.
(a)[4]
Outline the characteristic features found in the kingdoms Protista and Fungi.
(b(i))[3]
A student planned a method to measure the relative abundance of Usnea and Xanthoria on trees along a transect from the town centre at $0\,\text{km}$ to unpolluted countryside at $4\,\text{km}$. Suggest why measuring the relative abundance of the two types of lichen gives information that is useful for conservation.
(b(ii))[2]
Even though a high biodiversity of lichens occurs in many different habitats, most people overlook them. Outline why organisms that are usually overlooked, such as lichens, should be conserved.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “both belong to the eukaryotes / are in domain Eukarya” …