The reason phytoplankton have to live in shallow ocean water is because they cannot withstand the colder temperatures of deep water. they are an important food source to surface-dwelling marine organisms. they require sunlight to carry out photosynthesis. they feed on tiny organisms living at the surface.

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

Part a - which gene to compare? in this exercise, you will use the cytochrome c oxidase i (coi) gene to investigate relationships among salmon species. (this gene encodes a protein that functions in the mitochondrial electron transport chain.) you will compare the coi gene sequences from your salmon test samples to the standard sequences for each salmon species. in order for the coi gene to be useful for distinguishing among the different salmon species, which three statements must be true?

If this person had son,what,sex chromosome did they give their son? a.x b.y c.neither d.we need more information to know for sure