Igcse Model Questions Vol1 2018 Biology Question 3

A group of students investigated the effect of different carbohydrate solutions on the heart rate of the freshwater crustacean Daphnia magna. Five Daphnia were placed in each of three separate beakers containing: (i) distilled water (control), (ii) 5% glucose solution, and (iii) 5% sucrose solution. After a 5‑minute acclimatization period, the number of heartbeats in 60 seconds was recorded for each Daphnia. The data obtained are shown in the table below. | Solution | Daphnia 1 | Daphnia 2 | Daphnia 3 | Daphnia 4 | Daphnia 5 | |----------|-----------|-----------|-----------|-----------|-----------| | Distilled water | 120 | 115 | 118 | 122 | 119 | | 5% Glucose | 130 | 135 | 132 | 128 | 134 | | 5% Sucrose | 125 | 127 | 124 | 126 | 128 | Using this data, answer the following questions.