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Regulation

This reduces their ability to hunt for food,
evade predators, or perform other critical Procedure
behaviours that require high energy levels, 1. In pairs measure the temperature of
making them vulnerable during colder your partner while at rest and record it.
periods. 2. Ask your partner to run on the play-
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ground twice.
Ectotherms are also dependent on
environmental temperatures to regulate 3. Immediately after completing running,
their activity levels. In cold weather, they measure the temperature again and
must seek external heat sources, such as record it and compare it with the first
basking in the sun, to become active. This recording.
dependence on environmental conditions 4. Ensure your partner has rested for five
makes them particularly vulnerable to minutes then measure the temperature
predators when they are in a cold state again and record it.
and unable to move quickly. Furthermore, Observation
their need for specific temperature ranges What did you observe?
restricts their habitat preferences. Extreme
temperature conditions, either too hot or Questions
too cold, can be life-threatening, limiting 1. Was there any changes in temperature
the geographical range in which they can before and immediately after running?
survive. This constraint on habitat flexibility
can reduce their ability to thrive in climates 2. What caused the changes?
with extreme or unpredictable temperature 3. Explain the significance of regulation
fluctuations. of temperature in the human body.

Activity Conclusion
Investigating the effect of physical (a) Provide a conclusion for the
exercise on body temperature activity.
Materials (b) Write a short report of the activity.

Thermometer, stop watch and playing
ground

Exercise 5.3

1. Match the descriptions in Column B with the correct terms in Column A by
writing the letter of the correct response from Column B against the item number
in Column A.
Column A Column B
(i) Thermoregulation A. Narrow blood vessels reduce blood
flow to the skin, conserving heat

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