Vertebrate fossils found in Red Rock Canyon are from species that existed between about 12 and 8 million years ago. How could scientists have determined this? What can you learn about these fossils from the geologic timescale?

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

Amarine ecologist has constructed the conceptual model shown in the diagram. what predictions can be made from using this model? where the tertiary consumers get their energy how often primary producers are able to reproduce when bacteria and fungi initiate the process of decomposition whether other secondary consumers are present

Crossing over is a method of (blank)?