Daphnia were first placed in filtered pond water. After 30 minutes the Daphnia
were split into two groups. The first group was transferred to fresh, filtered pond
water (the control group). The second group was transferred to 5% ethanol (the
alcohol treatment group).
After another 30 minutes they were transferred back into filtered pond water and
left for a further 30 minutes.
The heart rate was recorded three times at 10 minute intervals for the entire
90 minutes of the investigation.
The student kept the temperature constant throughout the investigation.
Suggest a suitable temperature. Give an explanation for your answer.
Temperature
Explanation