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Daphnia (Daphnia pulex) is a species of water flea that lives in fresh water - Scottish Highers Biology - Question 2 - 2018
Question 2
Daphnia (Daphnia pulex) is a species of water flea that lives in fresh water. An investigation was carried out into the effect of water temperature on the heart rate... show full transcript
Worked Solution & Example Answer:Daphnia (Daphnia pulex) is a species of water flea that lives in fresh water - Scottish Highers Biology - Question 2 - 2018
Step 1
Calculate the average increase in heart rate per °C between 2 °C and 22 °C
Answer
To find the average increase in heart rate per °C, we first calculate the total increase in heart rate from 2 °C to 22 °C.
- Heart rate at 2 °C = 175 beats per minute
- Heart rate at 22 °C = 219 beats per minute
- Increase in heart rate = 219 - 175 = 44 beats per minute
Next, we determine the total temperature change:
- Temperature change = 22 °C - 2 °C = 20 °C
Now, we can calculate the average increase in heart rate per °C:
Step 2
Daphnia is a conformer. Use evidence from the table to confirm this statement.
Answer
Daphnia is considered a conformer because its heart rate increases as the water temperature increases. This can be observed in the table, where heart rates rise from 175 beats per minute at 2 °C to 219 beats per minute at 22 °C. This trend indicates that the metabolic processes of Daphnia are directly influenced by the external temperature.
Step 3
Explain how an increased water temperature would result in a higher metabolic rate in Daphnia.
Answer
An increased water temperature generally leads to a higher metabolic rate in Daphnia due to enhanced enzyme activity. As the temperature rises, enzyme performance increases, leading to more efficient metabolic reactions. Specifically, higher temperatures can promote optimal enzyme activity and oxygen delivery, which results in increased respiration and ATP production. Additionally, diffusion rates for oxygen and nutrients can increase at higher temperatures, further supporting metabolic activities.
Step 4
State the type of response shown by conformers to maintain an optimum metabolic rate.
Answer
The type of response shown by conformers, such as Daphnia, to maintain an optimum metabolic rate is a behavioral response. Conformers adjust their physiological processes to align with environmental changes, such as water temperature, without actively regulating their internal conditions.