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.
This is a controlled experiment because your goal is to keep every variable constant except the type of soil you use. You control these things! Why Controlled Experiments Are Important. The big advantage of a controlled experiment is you can eliminate much of the uncertainty about your results.