is bladderwort a producer of a consumer. An animal that can't produce its own food and it eats plants and other animals. That is what a consumer is.
If it is; What is the purpose of a control in verifying a hypothesis or conducting an experiment, it is: Controls are needed to eliminate alternate explanations of experimental results. That is in order to test a particular variable you need a control. For e.g.
Statistical power. The power of a binary hypothesis test is the probability that the test correctly rejects the null hypothesis (H0) when the alternative hypothesis (H1) is true.