Many different chemicals have been produced and widely used by society for the benefit of humans. However, oftentimes the chemicals have negative impacts on ecosystems. In paragraph form answer the following: Should chemicals continue to be used despite their impacts on ecosystems? Justify your answer and explain how three chemicals may impact (positive and negative) ecosystems and/or biodiversity of an ecosystem. (/7)

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