검증된 단계별 안내
02:37
04:48
01:43The main cause of the increase in the amount of CO₂ in Earth’s atmosphere over the past 170 years is
a. Increased worldwide primary production
b. Increased worldwide fertilizer production
c. Increased infrared radiation absorption by the atmosphere
d. The burning of fossil fuels and deforestation
Which of the following statements about protected areas established to preserve biodiversity is true?
a. About 25% of Earth's land area is now protected
b. National parks are the only type of protected area
c. Management of a protected area does not need to be coordinated with management of the surrounding area
d. It is especially important to protect biodiversity hot spots
Which of these is a consequence of biological magnification?
a. Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
b. Populations of top-level predators are generally smaller than populations of primary consumers.
c. The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers.
d. Only a small portion of the energy captured by producers is transferred to consumers.
What is the single greatest threat to biodiversity?
a. Overharvesting of commercially important species
b. Habitat alteration, fragmentation, and destruction
c. Introduced species that compete with native species
d. Novel pathogens
