A.大肠杆菌抗链霉素的突变是发生在与链霉素接触之后 |
B.在操作规范的情况下,5中观察到的菌落数可能大于初始接种到该培养基上的活菌数 |
C.4号和8号培养液中,大肠杆菌抗链霉素菌株的比例逐渐增大 |
D.该实验缺乏对照实验,无法确定抗链霉素性状属于可遗传变异 |

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

