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

Carbon dioxide functions as a greenhouse gas by .a. interfering with water's ability to absorb heat;b. increasing the random molecular motions of oxygen;c. allowing radiation from the sun to reach Earth and absorbing the re-radiated heat;d. splitting into carbon and oxygen and increasing the rate of cellular respiration

The main cause of the increase in the amount of CO2 in Earth's atmosphere over the past 150 years isa. increased worldwide primary production.b. increased worldwide standing crop.c. an increase in the amount of infrared radiation absorbed by the atmosphere.d. the burning of larger amounts of wood and fossil fuels.

Which of these statements best describes what conservation biologists mean by the 'the rapid loss of biodiversity'?a. Introduced species, such as starlings and zebra mussels, have rapidly expanded their ranges.b. Harvests of marine fishes, such as cod and bluefin tuna, are declining.c. The current species extinction rate is as much as 100 times greater than at any time in the past 100,000 years.d. Many potential medicines are being lost as plant species become extinct.

What community property doesthe red arrow in the model represent? a. low resilienceb. high resiliencec. low resistanced. high resistance

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.

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