Length, arm ratio and percentage of heterochromatin, and centromere position of chromosomes 3 and 4.

a[Total heterochromatin/total chromosome length]×100.bCentromere position (%) is (S/T)×100, where S = distance of centromere from the end of the short arm, and T = total length of chromosome.a. （总异染色质（Total heterochromatin）/染色体总长度（total chromosome length））×100。 b. 着丝粒位置（Centromere position）（百分比）为(S/T)×100，其中S为着丝粒至染色体短臂（short arm）末端的距离，T为染色体总长度。