【名词&注释】
核糖体(ribosome)、连接线(tie line)、沉降系数(sedimentation coefficient)、核心组蛋白(core histones)、连接组蛋白、真核细胞核
[单选题]真核细胞核糖体的沉降系数及其大小亚基的沉降系数分别是()
A. 80S,60S,40S B. 70S,50S,30S C. 80S,50S,30S D. 70S,40S,30S