State the relationship between sloth body temperature and ambient temperature.

Explain how this relationship differs from that in humans.

Describe the trend in body posture as ambient temperature rises from 22 to 34 °C.

Suggest reasons for this trend.

The mean daily food intake fluctuated from day to day. State the month that contains the day on which the mean intake of food was highest.

Outline the relationship between ambient daily temperature and food intake in March.

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

State one feature of the sloth that would indicate it is a mammal.

body temperature increases with ambient temperature / positive correlation;

Since direct can be either –/+, no credit for direct correlation alone.

humans maintain/regulate a constant body temperature at different ambient temperatures/maintained by homeostasis;

As ambient temperature increases, the sloth spends more time with limbs spread
OR
as ambient temperature increases the sloth spends less time curled in a ball
OR
as ambient temperature rises, the posture changes from 1 to 6;

1. less surface area is exposed when curled up
   OR
   more surface area is exposed when all limbs spread;
2. curled position prevents heat loss/provides warmth
   OR
   stretched out position allows more heat loss/body cooled;

May;

1. food intake rises as daily temperature increases / positive correlation;
2. the lowest food intake corresponds to the lowest temperature;

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.

1. mammals have mammary glands;
2. produce milk for their offspring;
3. bodies covered in hair/fur;

Characteristic must be exclusive to mammals.

If more than one answer, use the first one given.

Often steady or constant body temperatures for humans was given rather than homeostasis. Some candidates erroneously described humans as warming up in response to cold ambient temperatures.

There were a few beautiful responses where surface area was specifically incorporated into the answer achieving maximum marks.

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

Have hair/fur or feed young with milk were the best answers. Many students wrote "give birth to live young;" While this is true of most mammals, monotremes lay eggs. Furthermore, some other animals give birth to live young (ovoviviparous) such as some reptiles and some groups of fish. We credited only characteristics exclusive to all mammals.