下列选项能体现分离定律实质的是()
A.F1产生配子之比为1:1
B.F2显隐性之比为3:1
C.F2的基因型之比1:2:1
D.F1测交后代显隐性之比为1:1
参考答案:A
—What is the matter to you?
—I ______ .[ ]
A. get a headache
B. have a headache
C. got a stomachache
D. have good grades
小管液中渗透浓度变化最大的部位是()
A.近端小管远段
B.近端小管近段
C.髓袢升支粗段
D.髓袢降支细段
E.内髓结合管