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Compare the variation in body temperature of the echidna in warm weather with the variation in body temperature of the human - AQA - GCSE Biology - Question 8 - 2022 - Paper 1
Question 8
Compare the variation in body temperature of the echidna in warm weather with the variation in body temperature of the human. Use data from Figure 11 and Figure 12.... show full transcript
Worked Solution & Example Answer:Compare the variation in body temperature of the echidna in warm weather with the variation in body temperature of the human - AQA - GCSE Biology - Question 8 - 2022 - Paper 1
Step 1
Compare the variation in body temperature of the echidna in warm weather with the variation in body temperature of the human.
Answer
The body temperature of the echidna during warm weather fluctuates significantly, ranging from about 27 °C to 35 °C, as shown in Figure 11. In contrast, the human body temperature, depicted in Figure 12, remains relatively stable, fluctuating only between 36.2 °C and 37.2 °C. This indicates that the echidna has a much greater variation compared to the human, which maintains a more constant and narrow range of body temperature.
Step 2
Explain why the decrease in body temperature is an advantage to the echidna during hibernation.
Answer
The decrease in body temperature during hibernation is advantageous for the echidna as it reduces metabolic rates, allowing the animal to conserve energy. By lowering energy expenditures, the echidna can survive longer periods without food as it relies on fat reserves, supporting physiological functions during winter months when food is scarce.
Step 3
Explain why the echidna has a higher body temperature when it is active.
Answer
When the echidna becomes active, its body temperature rises above 30 °C due to increased metabolic activity. Activity requires energy which is derived from respiration, resulting in heat production. This elevated metabolism enhances physiological processes, thereby raising the overall body temperature of the echidna.
Step 4
Explain how the dilation of blood vessels in the skin can help to decrease body temperature.
Answer
Dilation of blood vessels in the skin allows for increased blood flow to the surface, facilitating heat loss from the body. As blood vessels expand, more blood reaches the skin, where heat can be dissipated into the environment. This mechanism is crucial for thermoregulation, especially in warm conditions, helping to lower body temperature effectively.
Step 5
Calculate the volume of sweat the athlete lost each day.
Answer
The daily energy used for evaporation of sweat is 40% of the athlete's total energy intake. Therefore, this is calculated as:
Since evaporation of 1 cm³ of sweat requires 2.5 kJ of energy, the volume of sweat lost can be computed:
ext{Volume of sweat} = rac{8,000 ext{ kJ}}{2.5 ext{ kJ/cm}³} = 3,200 ext{ cm}³
Converting to dm³:
ext{Volume of sweat} = rac{3,200 ext{ cm}³}{1,000 ext{ cm}³/ ext{dm}³} = 3.2 ext{ dm}³
Step 6
Suggest why the athlete was advised to take salt tablets each day.
Answer
The athlete was advised to take salt tablets each day to replace ions lost through sweat. Sweating leads to loss of not only water but also essential electrolytes such as sodium and potassium, which are vital for maintaining hydration, nerve function, and muscle contraction. Supplementing with salt tablets can help prevent muscle cramps and ensure optimal performance.