(1)实验一:具体操作见下图。

该实验设置第④组的目的是
(2)实验二:在小麦胚芽鞘上用记号笔面等距横线(A组)或涂抹透光指甲油(B组)并用单侧光照射,具体操作见下图。

一段时间后,可预测A组胚芽鞘
(3)实验三:具体操作见下图。(注:切去胚芽鞘尖端后放回原处或在切口处放一琼脂块)

图中①②向光弯曲生长,且②组的弯曲角度小于①,推测原因是

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

