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.
Structure - The largest organelle in the cell. It is dark and round, and is surrounded by a double membrane called the nuclear envelope/membrane. In spots the nuclear envelope fuses to form pores which are selectively permeable. The nucleus contains genetic information (DNA) on special strands called chromosomes. Function - The nucleus is the control center of the cell, for cell metabolism and reproduction. the following organelles are found in both plant and animal cells.