Chromosomes are usually 3.5-30 µm in length and 0.2-2.0 µm in diameter. Average human chromosome length is 4-6 µm, Drosophila chromosome length is 3 µm and Bhutra chromosome length is 8-12 µm. Lamp brush chromosomes are 1500-2000 micrometers in length. Polytene chromosomes are 2000 micrometers in length. Chromosome length of Trillium is 32 µm. At the metaphase stage of cell division, the chromosomes are thick, well-organized and clearly visible.