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Lichen Biology Questions

Question 1

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Answer 1

Definitely. Even though a single thallus may consist of different fungal isolates, and different photobionts, the fungi all have specific signals with their partners, and are thus likely to be closely related. The majority of the thallus is likely to be of one genotype and therefore consistent in its physiological and structural attributes. The use of a species name, however, must be tempered by the possibility that it need not refer to a single partner of fungus and photobiont.


Question 2

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Answer 2

The most likely explanation is that the air is unpolluted with anything that affects the lichen. Many pollutants will kill lichens, but maybe some have adapted to specific pollutants, or exist on surfaces that protect the thallus from absorbing the pollutant.


Question 3

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Answer 3

Thalli can consist of more than one type of fungus and photobiont. Thus the change in colour indicates different secondary metabolites, and the raised section indicates different morphology. Together, they suggest a thallus of mixed fungi, and possible photobiont. Alternatively, the edge may have been loosened by a physical process, died and remained raised. Lichens can change colour after death.


Question 4

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Answer 4

Reindeer, exist in the arctic circle, eating mostly lichens. Thus any pollution retained by the lichen will be passed on to the reindeer. Radioactive caesium was released to the air by the Chernobyl accident, and may have been deposited over the lichens. Thus the lichens may have concentrated the radioactive caesium, which is then passed on to the reindeer. The consequences include decline in quantities of lichen and survival of the reindeer.


Question 5

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Answer 5



Question 6

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Answer 6



Question 7

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Answer 7