1) Which of the following ecological locations has the greatest species diversity?
A) tundra
B) deciduous forests
C) tropical rain forest
D) grasslands
E) islands

2) Invasive species are introduced by humans to new geographic locations and
A) are successful in colonizing a novel area.
B) spread because they encounter none of their natural predators.
C) All of the choices are correct.
D) can outcompete and displace native species for biotic and abiotic resources.
E) are usually considered pests by ecologists.

3) Estimates of current rates of extinction
A) indicate that we have reached a state of stable equilibrium in which speciation rates equal extinction rates.
B) suggest that one-half of all animal and plant species may be gone by the year 2100.
C) indicate that rates may be greater than the mass extinctions at the close of the Cretaceous period.
D) indicate that only 1% of all of the species that have ever lived on Earth are still alive.
E) suggest that rates of extinction have decreased globally.