The graph models the effect of an environmental stimulus on temperature control in mammals - HSC - SSCE Biology - Question 9 - 2005 - Paper 1

As the environmental stimulus is introduced, there is a noticeable increase in body temperature, which peaks after a certain time before it begins to decrease. This indicates that mammals experience physiological changes in response to environmental cues.

Mammals regulate their body temperature through homeostasis. When exposed to an environmental stimulus, like heat, the hypothalamus triggers mechanisms including sweating and vasodilation to dissipate heat and return the body temperature to normal levels. Conversely, if the temperature decreases, mechanisms such as shivering and vasoconstriction are activated.