One of the differences between embryonic stem cells and adult stem cells is ?

Environmental differences within ecosystems are generally caused by

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

Can a trait be both polygenic and have multiple alleles? explain why or why not.