In a Controlled Experiment,____________

question 34

Multiple Choice

In a controlled experiment,____________.

• A)the researcher has several hypotheses, one of which will be proven correct
• B)you need only a single experimental organism which is tested again and again
• C)the researcher knows the outcome before beginning the experiment
• D)the researcher controls for the effects of only one variable
• E)the researcher controls for the effects of all variables except one

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Definitions:

Gastrovascular Cavity

A central cavity in certain simple animals that functions in both the digestion and distribution of nutrients.

Cnidarians

A phylum of aquatic invertebrates that includes jellyfish, corals, and sea anemones, characterized by a simple body plan with a single opening and cnidocytes for capturing prey.

Hydras

Freshwater organisms belonging to the phylum Cnidaria, known for their simple tubular body and radial symmetry.

Complete Digestive System

A digestive system that has two separate openings for ingestion and egestion, allowing for a one-way flow of food and efficient digestion.