Dr. alley is pointing to a brownish zone exposed in the low bluff along coast guard beach, cape cod national seashore. the brown zone is rounded on the bottom, flat on the top, rests on sand and gravel, and has sand dunes on top. in the lower picture, dr. alley is showing that the brown zone contains twigs and other organic material. what is the brown zone doing here? a) a sinkhole opened here, forming a lake that was then filled with organic material. b) an ice block from the glacier was buried in sand and gravel, then melted to make a lake. c) humans dammed a nearby river, forming a lake that then filled with organic material. d) the brown zone is mostly the carcass of a dead whale, which washed up on the beach. e) the brown zone is mostly the carcass of a dead whale, which was propelled here when that filled with organic material. was buried. highway-department workers dynamited it to get it off the beach.

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein

The open ocean begins at the low-tide mark and extends to the end of the continental shelf

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.