Which kind of energy comes from sources that won't run out?

Agenus is a taxonomic grouping that identifies a collection of species. when a scientist discovers a new species, how is this species assigned to a genus

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas

Describe the structure of amino acid, including what makes amino acids different from eachother