Cactus

We're Mark and Alex, and we're junior docents at the Arizona - Sonora Desert Museum. We do presentations for museum visitors about the plants and animals you can see here, especially the saguaro cactus. One visitor asked a question about the holes that are visible in the arms of the cactus: Do the holes in a saguaro cactus always face the same direction?

How would you investigate this question?
Even if you don't live near a saguaro cactus forest, you can design an experiment to answer Mark and Alex's question. How many cactus should you look at? Is the direction the nest faces the only important factor? What about diameter of the nest, or how high above the ground it is? Make decisions about which information is important, and which is not. Describe your investigation in your notebook and discuss it with your teacher, or go to Cactus to learn what Mark and Alex discovered.