Question

the amount of expansion of the dough in each cylinder was measured after 15 minutes. the results are shown in the data table below.

the effect of temperature on yeast respiration

temperature of water bath (°c)	10	25	50	75	90

• mark an appropriate scale, without any breaks, on the axis labeled \temperature of water bath (°c)\ (20)
• plot the data from the data table. surround each point with a small circle and connect the points. (20)

questions:

• identify the independent variable in this investigation. (20)
• at which temperature did yeast cells produce the least amount of gas in 15 minutes? ______ °c (20)

Explanation:

First Question: Identify the independent variable in this investigation.

In an experiment, the independent variable is the one that is manipulated or changed to observe its effect on another variable. Here, the investigation is about the effect of temperature on yeast respiration (change in volume of bread dough). So the temperature of the water bath is the independent variable as it's the factor being varied to see its impact on the dependent variable (change in volume).

To find the temperature with the least gas production, we look at the "Change in Volume of Bread Dough (mL)" column. The smallest value here is 2 mL, and the corresponding temperature in the "Temperature of Water Bath (°C)" column is 90°C.

Answer:

Temperature of Water Bath (°C)

Second Question: At which temperature did yeast cells produce the least amount of gas in 15 minutes?