What is the term for a structure that has no use in an organism

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a. coral reefs because of the loss of the symbiotic algae living within their bodies b. penguin populations because the fish they eat will move into warmer waters c. mountain-dwelling birds because rising sea levels will relocate their food sources d. large cats in the rainforest because of decreased habitat loss for their prey

Fill in the blank with the best word to complete the sentence. white blood cells protect against and aid in blood clotting when injuries are sustained.