High rates of species extinction caused by human activity have taken place at which of the following times in Earth’s history?

Oxygen has 3 stable isotopes – Oxygen-16, Oxygen-17, and Oxygen-18. How many protons does Oxygen-18 have?

The San Andreas Fault in California is an example of a ______________.

Looking at the ecological pyramid above, what would be the most likely number of joules to fill in x, y, and z?

A population of rabbits, introduced to an island, has rapid growth for a few years and then slows. What is a likely reason for this pattern?

Which of these human behaviors is most likely to lead to the tragedy of the commons?

Describe what an ecological footprint is. Describe how the ecological footprint of a more developed country would differ from a less developed country. (Make sure to clearly describe each answer and write in complete sentences.)

Choose the correct sequence for energy flow in an ecosystem.

The California Department of Fish and Wildlife is developing a plan to connect mountain “habitat islands” that are separated by open areas of flat, arid land in the deserts of southeastern California. These mountain areas are habitats for desert bighorn sheep (Ovis canadensis), which move extensively among the islands through habitat corridors. The habitat corridors provide opportunities for recolonization, seasonal migration, and maintenance of genetic variation among the metapopulation of desert bighorn sheep.   (a) Describe one density-dependent factor and one density-independent factor that could affect the populations of desert bighorn sheep. (Make sure to clearly describe your answers and write in complete sentences.)

On the pH scale 5 is _________ and 10 is ________.