Antibiotics are designed to target only the cells that are harmful to the human body
If a hypothetical poison prevent nucleoli from carrying out their functions, the cell organele that will be affected is the RIBOSOMES.
Nucleoli of the cell is the one that is responsible for production of ribosomal sub units; it uses proteins and ribosomal RNA to do this. It then send the sub units to the interior of the cell where they are assembled.
Ribosomes make proteins in the cells. Thus, if nucleoli is affected, ribosome will not be produced and ultimately proteins will not be produced in the cells.
Water in the ocean move differently depending of the win speed. In the ground, it only moves downward due to gravity pulling in the water while the soil absorbs the water. Water above ground only go one direction due to the slope of the mountain or riven.
A desert would be a good example because there is no exact source of water there unless you are in a specific one.