Question

Students hypothesized that water pollution affects the growth of fish. in an experiment, they added the same amount of food to ponds polluted by fertilizers and industrial waste. they measured fish growth and found that most fish grow more slowly in each of these environments. what part of their experiment did they forget to include?

Answer 1

The part of which made the experiment gone wrong was because they forget to include of having a group that would serve as the control—this is essential in their experiment so that they may be able to determine the effects of the growth of fish in different environments but because they don’t have the group to serves as control, they only have found out that all fishes grow slowly despite with given different environments.

Answer 2

The correct answer will be control group.

Step-by-step explanation:

A scientific experiment is designed in such a way that it should include two types of groups: the experimental group in which the variable has to be tested and the control group in which the variable to be tested is kept constant.

Since in the given question, the experiment was performed to test that water pollution affects the growth of fish, so the independent variable will be the "pollution".

The experiment was performed in which pond was polluted with fertilizers which will provide the experimental data but he forgot to prepare a control group which will provide the reference to the experimental data.

Thus, the control group is the correct answer.