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.
If the experimenter is aware of the hypothesis of the experiment, it is more likely that the hypothesis will be confirmed. The experimenter-bias effect can be controlled by keeping not only the subjects (single-blind) but also the experimenter blind to the hypothesis. This is called the double-blind procedure.