Biology 9700 · AS & A Level · Investigation of limiting factors
Investigation of limiting factors — practice question
A lichen is a symbiotic partnership in which a fungus lives with an organism called a photobiont, to the advantage of both partners. One photobiont is the green alga Trebouxia sp., a photosynthetic protist. Fig. 8.1 illustrates lichen growing on a tree.
(a)[4]
Outline the defining characteristics of the kingdom Fungi.
(b)[2]
Suggest how a fungus and a green alga each benefit from the association shown in a lichen.
(c(i))[1]
State which photosystem is responsible for oxygen release.
(c(ii))[4]
With reference to Fig. 8.2:
• explain the section of the curve between A and B;
• explain why it becomes level after C.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Eukaryotic; true nucleus present” …