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Question 22M.2.SL.TZ1.1h

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Date May 2022 Marks available [Maximum mark: 1] Reference code 22M.2.SL.TZ1.1h
Level SL Paper 2 Time zone TZ1
Command term Suggest Question number h Adapted from N/A
h.
[Maximum mark: 1]
22M.2.SL.TZ1.1h

Three-toed sloths (Bradypus variegatus) are placental mammals that live in trees in Central and South America. They eat leaves and fruit and get almost all their water from succulent plants.

[Source: Adapted from Laube, S., 2003. Three-toed-sloth (Bradypus variegatus), Lake Gatun, Republic of Panama. [image online] Available at: https://meta.wikimedia.org/wiki/User:Bradipus#/media/File:Bradypus.jpg] 

Three-toed sloths change their body posture in response to the temperature of their environment (ambient temperature). Researchers assessed posture on a scale from 1 to 6, with 1 being when the sloth was curled into a tight ball and 6 when it had all limbs spread. The percentage of time the sloths were observed in each position was recorded at ambient temperatures from 22 °C to 34 °C. The researchers also measured the body temperature of the sloths over the same range of ambient temperatures.

[Source: Adapted from Cliffe, R.N., Scantlebury, D.M., Kennedy, S.J., Avey-Arroyo, J., Mindich, D. and Wilson, R.P., 2018. The metabolic response of the Bradypus sloth to temperature. PeerJ, [e-journal] 6: e5600. http://dx.doi.org/10.7717/peerj.5600. Licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/.]

The daily food intake of three-toed sloths and daily ambient temperatures were monitored over a 160-day period from February to early July. The graphs show the mean results.

[Source: Cliffe et al. (2015), Sloths like it hot: ambient temperature modulates food intake in the brown-throated sloth (Bradypus variegatus). PeerJ 3:e875; DOI 10.7717/peerj.875 Licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/.]

(h)

Suggest, with a reason, how the activity of the sloth varies with ambient temperature.

[1]

Markscheme
  1. the sloth will be more active at higher temperatures as it takes in more food for energy;
  2. as temperature rises, the sloth uncurls to dissipate/lose heat;

Reason required.

Examiners report

Good reasoning was not seen often, best answers needed some of the elements in this linkage: higher temperature led to uncurling which led to movement which led to eating because of energy needs; "sloth prefers staying curled up so cold does not affect them" or "sloth enjoys staying curled up" were not acceptable