Biology 5090/31 — May/June 2018
Cambridge O-Level · Practical Test · worked solutions for every part, with the mark scheme
Topics Experimental Contexts · Observations and Measurements · Analysis, Conclusions and Evaluation · Microscopy and Biological Drawing · Use of Techniques, Apparatus and Materials · Planning Experiments and Investigations
You are going to investigate heat loss from the outer surface of the bodies of two animals.
You are provided with a large test-tube and a small test-tube to represent the two animals.
The large test-tube has a lower surface area to volume ratio.
The small test-tube has a higher surface area to volume ratio.
When you are ready, place the two test-tubes in a rack or beaker and raise your hand. The Supervisor will pour hot water into the two test-tubes.
Caution: the test-tubes will be hot.
Immediately measure the temperature of the water in each test-tube and record your measurements in the table.
After 2 minutes, measure the temperature of the water in each test-tube again and record your measurements in the table.
Measure the temperature of the water in each test-tube every 2 minutes for 10 minutes and record your measurements in the table.
| Time / minutes | Temperature / | |
|---|---|---|
| Large test-tube | Small test-tube | |
| 0 | ||
| 2 | ||
| 4 | ||
| 6 | ||
| 8 | ||
| 10 |
Describe how your results could be made more reliable.
______
On the grid below and using one set of axes, construct a graph with two lines to show the relationship between time and temperature of the water in the two test-tubes.
Join your points with ruled, straight lines.
Use your graph to determine the temperature of the water in the large test-tube at 3 minutes.
Show your working on your graph.
______
Describe what you can conclude about heat loss in large and small animals from your results.
______
Penguins are animals that need to maintain a constant body temperature. They can be found living in cold climates near the South Pole as well as in the warmer climate of New Zealand.
Using the results of this investigation, suggest and explain:
what difference there may be in the size of the penguins found in these two areas,
size = ______
explanation = ______
why penguins stand very close together in groups when external temperatures are very low.
______
The rest of this paper
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