Which statement best explains why each river has its own set of characteristics? Rivers flow downhill, pulled by gravity toward the sea.
Rivers interact with the ecosystems through which they pass.
Rivers absorb oxygen from the atmosphere as they flow downhill.
Rivers have climates that are determined by the biomes they flow through.

What do we call an individual that has inherited two identical alleles for the same trait? a.homozygous b.heterozygous c.monozzygous

Which characteristic should describe all evidence collected by a scientist? true obvious objective subjective

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