Which of the following examples of an ecological study involves the ecosystem level of organization?

a. the effects of human activities on biogeochemical cycling
b. the effects of a disease on population size
c. the effects of an invasive plant species on bird nesting sites
d. the effects of competition on survival

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Which nucleotide component contains nitrogen

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food