Page 17 - 新思维科学活动用书8 样章

1 Respiration

1.4 Respiration

Exercise 1.4 Respiration by yeast

In this exercise, you will think about how to choose apparatus, and the correct way to use a
thermometer. You make a prediction about temperature change and also think about using this

apparatus to plan an experiment to test a hypothesis.

Focus

Yeast is a living microorganism. Sofia wants
to find out what happens to the temperature

of yeast when it respires.
She has some yeast mixed with water.
She measures 25 cm of the mixture and
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puts it into an insulated cup.
Then she adds 25 cm of sugar solution.
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1 One piece of apparatus that Sofia
needs is missing from the diagram.
State what this apparatus is, and

why Sofia needs it.

2 Sofia measures the temperature of the mixture of yeast and sugar solution in the cup.
How should Sofia measure the temperature?

Tick (✓) all the correct statements.

Make sure that her eyes are level with the meniscus in the thermometer to read the
temperature.

Stand the thermometer in the cup so it is resting on the bottom.

Hold the thermometer in the liquid and stir gently.

Make sure her eyes are level with the meniscus to read the temperature.

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