Though change is always occurring in ecosystems, ecological succession is considered complete when an community is established. A Cli max
B Pr imary
C Im portant
D A pex

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes