Which of the following is a characteristic of vertebrates? a. stinging cells b. an inner skeleton made of bone or cartilage c. a hard exoskeleton made of chitin d. a hard outer shell

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays

Long term exposure to waves can cause sunburns and skin cancer.

Ronald wants to see if a new shower cleaner works better in removing soap than his old cleaner. he uses the new cleaner on one half of the shower tiles and his old cleaner on the other half. identify the independent and dependent variables in this experiment. enter your answer in the space provided.