Which of the following statements best defines the term operon?
a. an operon is a region of dna that consists of a single gene regulated by more than one promoter. b. an operon is a region of dna that codes for a series of functionally related genes under the control of the same promoter. c. an operon is a region of dna that codes for sugar-metabolizing enzymes. d. an operon is a region of rna that consists of the coding regions of more than one gene.

Fill in the blank 1. digestion occurs in the small intestine through the action of enzymes. 2. urea, excess water, and other waste materials are eliminated in a water fluid called 3. can cause infections by injecting dna or rna into hosts. 4. the human immune system produces in response to a vaccine, which later can bind to and destroy a pathogen if it invades. 5. are structures that link bone to bone at a joint 6. in the heart, blood flows from the right atrium to the right ventricle, where it is pumped to the the words i can use are: lymphocytes gliding pivot gas urine absorption dermis fulcrum lungs chemical viruses capillary vertebrae esophagus tendons antibodies synapses ligaments kidneys pathogens