The Latin name is from the Japanese name for T. sieboldii. T. canadensis and T. heterophylla were discovered early (before 1800) and until 1855 were simply treated as species of Pinus, but in 1842 T. sieboldii, the southern Japanese hemlock, was described as Abies tsugae.
The brains of the cell, the nucleus directs cell activities and contains genetic material called chromosomes made of DNA.
The three organelles that contain DNA are the nucleus, mitochondria and chloroplasts. Organelles are membrane-bound subunits within a cell -- analogous to organs in the body -- that perform specific functions. The nucleus is the control center of the cell, and houses genetic information.