duō / xiàn / rǎn / sè / tǐ / yǒu / zhù / yú / yán / jiū / jī / yīn / zài / rǎn / sè / tǐ / shàng / de / pái / liè多线染色体有助于研究基因在染色体上的排列。Polytene chromosomes help researchers study how genes are arranged on chromosomes.