A scientist performs a controlled experiment. This means that
A) the experiment is repeated many times to ensure that the results are accurate.
B) one experiment is performed, but the scientist controls the variables.
C) two experiments are conducted, one differing from the other by only a single variable.
D) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
E) two experiments are conducted, one differing from the other by two or more variables.
A) the experiment is repeated many times to ensure that the results are accurate.
B) one experiment is performed, but the scientist controls the variables.
C) two experiments are conducted, one differing from the other by only a single variable.
D) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
E) two experiments are conducted, one differing from the other by two or more variables.
-
quite confusing options...
According to me its C
According to me its C
-
C. A control is an experiment set up with identical conditions as the original except without the independent variable (i.e what you are testing). The reason why it is important is so that you can determine that the results obtained are due to the factor being investigated and not due to an external factor.
In a controlled experiment, all confounding/control variables (external factors which may effect the results e.g. temperature, pH) are kept constant by the scientist.
For example, in an experiment to investigate the effect of light on the rate of transpiration, 2 experiments are set up. One will be in light and the other will be in the absence of light. All other factors are kept constant, so the 2 experiments occur in identical circumstances. This will show whether it really is the presence of light which affects transpiration rate.
Sorry about the length but hope that helps x
In a controlled experiment, all confounding/control variables (external factors which may effect the results e.g. temperature, pH) are kept constant by the scientist.
For example, in an experiment to investigate the effect of light on the rate of transpiration, 2 experiments are set up. One will be in light and the other will be in the absence of light. All other factors are kept constant, so the 2 experiments occur in identical circumstances. This will show whether it really is the presence of light which affects transpiration rate.
Sorry about the length but hope that helps x
-
E)