The cubic kilometer is a metric unit of volume equal to 1,000,000,000 cubic meters. The symbol of the cubic kilometer is kmÂ³ . km3 = 1,000,000,000 m3 = 109 m3. To convert cubic kilometers to hmÂ³, damÂ³, mÂ³, dmÂ³, cmÂ³ and mmÂ³ , multiply by one followed by as many trios of zeros as there are places between the cubic kilometer and the other unit.
Rod photoreceptors are very sensitive to light and are responsible for night vision. These are the most abundant cell type in the human retina and are located closest to the back of the eye, near the retinal pigmented epithelium (RPE).
A) cone cells can detect color, but rod cells cannot. B) cone cells are more sensitive than rod cells to light. C) cone cells, but not rod cells, have a visual pigment. D) rod cells are most highly concentrated in the center of the retina. E) rod cells require higher illumination for stimulation than do cone cells.