Page 339 - Biology_F5

Biology for Advanced Level Secondary Schools

Questions is termed as temperature regulation
(thermoregulation). Animals with a
1. Compare the time taken for the varying body temperature according to the
bunch and individual bananas to changes in the environmental temperature
ripen. are called poikilotherms (poikilos means
2. What might be the cause of the ‘various’ and thermo means ‘heat’). These
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differences in ripening time? animals obtain most of their body heat
3. Explain the significance of the from the sources outside their bodies;
phenomenon in our everyday life. hence they are sometimes referred to as
ectotherms. Examples of poikilothermic
4. Prepare a scientific report on this
investigation. organisms include reptiles, amphibians
and most fish. With exception of birds and
mammals, most animals are ectotherms.

Exercise 7.1 Animals that maintain a stable body
temperature regardless of fluctuations
1. Imagine you meet a young man in the environmental temperature are
carrying a heavy luggage in severe called homoiotherms or homoeotherms
hot weather and have no water to or homeotherms. Their heat is generated
drink. How can his body survive in internally by metabolic activities; hence,
this adverse condition? they are also known as endotherms; and
2. Describe the components of they include mammals and birds. The
homeostatic control mechanism in body temperature of endotherms ranges
your body when subjected to various between 37 °C and 44 °C. The higher the
adverse environmental conditions. body temperature, the greater the metabolic

3. How would you demonstrate your rate in the animal’s body becomes. For
understanding on the feedback example, birds have higher metabolic rate
mechanisms involved in homeostatic to cater for the energy needed for flight.
control? Their body temperature ranges between

4. With example explain the negative 38.5 °C and 44 °C. Homoeotherms can
feedback control system and clearly regulate their body temperature through
describe how it works. negative feedback control. They control
their body temperature independent
7.2 Temperature regulation of the environment; they use internal
Most organisms can survive in a narrow physiological control mechanisms, as
range of temperature from 10 °C to 30 °C. well as behavioural mechanisms.
In order to survive, most animals have
to regulate their body temperature. The Adaptation of endotherms to cold and
tendency of animals to adjust their body hot climatic conditions
temperature to suit the living conditions of In order to survive in a variety of habitual
varying temperatures in the environment environments, species of mammals have
developed various physiological adaptive

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