| Date | May 2017 | Marks available | 2 | Reference code | 17M.3.SL.TZ2.1 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Predict | Question number | 1 | Adapted from | N/A |
Question
The oxygen consumption rate of the fish Oplegnathus insignis was examined in a respirometer at three different water temperatures and at four different body masses.
Suggest how the oxygen consumption rate is determined using this apparatus.
State the relationship between body mass and the oxygen consumption of fish.
Predict the effects of global warming on aerobic respiration in fish.
Markscheme
a. the data logger measures the differences in oxygen concentration
OR
the oxygen concentration is measured before and after the water passes through the respirometer
b. over time
c. the mass of fish needs to be measured
greater body mass, less consumption of oxygen
OR
indirect/negative relationship
a. higher temperature, more oxygen consumption
b. «more oxygen consumption» is due to more respiration/metabolism
c. less oxygen can dissolve in warmer water so less «aerobic» respiration
OR
more carbon dioxide dissolved so less oxygen for respiration
