Which of the following currently poses the single greatest threat to biodiversity?a. invasive speciesb. overhuntingc. habitat lossd. pollution

A mass extinction .a. is global in scale;b. affects many different groups of organisms;c. is caused only by human activity;d. A and B are correct;e. A, B, and C are correct

An ecological footprint .a. is the position an individual holds in the ecological food chain;b. estimates the total land area required to support a particular person or human population;c. is equal to the size of a human population;d. helps determine the most appropriate wastewater treatment plan for a community;e. is often smaller than the actual land footprint of residences in a city

What is the single greatest threat to biodiversity?a. overharvesting of commercially important speciesb. habitat alteration, fragmentation, and destructionc. introduced species that compete with native speciesd. novel pathogens

The discipline that applies ecological principles to returning degraded ecosystems to a more natural state is known asa. restoration ecology.b. thermodynamics.c. eutrophication.d. biogeochemistry.

What is a biodiversity 'hotspot'?a. an area where an all-taxon survey is under wayb. an area where an environmental sequencing study has been completedc. a habitat with high NPPd. an area with high species richness and high threat to those species

The burning of fossil fuels .a. releases carbon dioxide to the atmosphere;b. primarily occurs as a result of human activity;c. is contributing to global warming;d. is possible thanks to photosynthesis that occurred millions of years ago;e. all of the above are correct

Current rates of species extinction appear to be approximately historical rates of extinction.a. equal to;b. 10 times lower than;c. 10 times higher than;d. 50 to 100 times higher than;e. 1000 to 10,000 times higher than

Which of the following is characteristic of endemic species?a. They are often found in biodiversity hot spots.b. They are distributed widely in the biosphere.c. They require edges between ecosystems.d. They are often keystone species whose presence helps to structure a community.