Cities fall under the category of urban ecosystems. urban ecosystems include nature, humans, and animals in a (mostly) human-built environment. energy flow, nutrient cycles, and resource use are all necessary to maintain an urban ecosystem. most urban ecosystems are heterotrophic because they depend on materials and energy from outside their boundaries.

the significance of this reliance on outside resources is ―

what in the weirdo : o

voluntary muscles are controlled by the cerebellum.

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: