Biodiversity Distribution

What is often used as the most easily measured component of biodiversity?

• Species diversity

• Habitat diversity

• Genetic diversity

• Ecosystem diversity

How many species of plants, animals, fungi, and microorganisms have scientists identified and described so far?

• About 3 million to 4 million

• About 1.7 million to 2 million

• About 500,000 to 1 million

• About 2.5 million to 3 million

What percentage of known insects are beetles?

• About 30%

• About 25%

• About 50%

• About 40%

Which pattern is described as a general increase in species richness toward the equator?

• Species richness gradient

• Ecosystem diversity gradient

• Latitudinal gradient

• Habitat diversity gradient

Why do estimates of the total number of species on Earth vary so much?

• Some areas remain relatively unexplored

• Many species are tiny and easily overlooked

• Organisms are difficult to identify and tell apart

• All of the above