A student wanted to compare germinating pea seeds (growing) and nongerminating pea seeds (not growing). She wanted to test
two variables: germinating vs nongerminating peas at two
different temperatures: 10° C and 25° C.
The student proceeded to set up two electronic water baths: a
warm water bath (25° C) and a cold-water bath (10°C). She also
set up four respirometers: two containing germinating peas and
two containing non-germinating peas. Where would she need to
place the respirometers in terms of water baths to ensure that she
was setting up a controlled experiment?