Question 18M.2.HL.TZ1.1c.ii
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.HL.TZ1.1c.ii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Evaluate | Question number | c.ii | Adapted from | N/A |
White-nose syndrome (WNS) is a disease caused by the fungus Geomyces destructans. This kills bats from many species during their winter hibernation Scientists used echolocation to record the number of bat flights over a station in 10 minute sample periods during the summers of 2007 to 2009. The graph shows the mean number of flights and number of recording samples for little brown bats (Myotis lucifugus), a species affected by the fungus, along with those of hoary bats (Lasiurus cinereus), which are not affected.
Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.
[2]
Conclusion supported
(2008 to 2009) M. lucifugus declines more (than L. cinereus)
OR
(2007 to 2009) M. lucifugus declines whereas L. cinereus increases/fluctuates/did not decline
OR
more affected than unaffected bats in 2007 and 2008 but more unaffected in 2009
Conclusion not supported
other factors could be causing the difference between the species/the decrease in M. lucifugus
OR
there will be differences between the two bat species apart from WNS infection
OR
both species decreased from 2008 to 2009
Award one mark maximum for an argument supporting the conclusion and one mark maximum for an argument against the conclusion. Marks should only be awarded for statements that make an explicit or clearly implied comparison between the species.
