What does ecosystem diversity describe?

• The variety of ecosystems across a region
• The inherited differences within a single species
• The number of different species in one habitat

What does species diversity describe?

• The inherited differences among members of one species
• The number of species and their relative numbers of individuals
• The variety of ecosystems and their living conditions across a region

Inherited differences among individuals of the same species are part of genetic biodiversity.

A town clears woodland, releases toxic waste into a river, and burns fossil fuels that add greenhouse gases. Which set correctly names the three biodiversity pressures?

• Habitat loss, pollution, and climate change
• Overharvesting, pollution, and climate change
• Habitat loss, invasive species, and overharvesting

Two meadows have the same flower species. Meadow A has four pollinator species; Meadow B has one. A disease removes one pollinator species from each meadow. Why might pollination continue in A?

• A lower need for pollen in flowers after one of their pollinator species disappears.
• Immunity to the disease in the remaining insects due to a larger pollinator species count.
• Continued visits by surviving pollinator species that carry pollen between the flowers.

These invented surveys used the same method in the same area before and after the habitat was replaced by a parking lot. What do the species counts show?

• Species richness rose by eleven species.
• Species richness fell from fourteen species to three.
• Species richness stayed the same because both surveys found life.

A company clears a rainforest for farmland. It says the loss does not matter because the same species survive in other forests. Why should nearby people still care?

• Local food webs and benefits such as water filtering can be lost.
• Species surviving elsewhere replace this forest's local benefits.
• Farmland has more biodiversity than the cleared forest.

Jordan says an introduced plant cannot reduce biodiversity because it adds a species. The plant crowds out several native plant species, which disappear locally. Which explanation addresses his claim?

• The introduced plant adds more species than the native plants lost.
• An introduced species and the native species it replaces count as the same species.
• Native species losses can outweigh the one species added.