
(1)图中能产生花粉的结构是[ ]
(2)一朵已授粉的桃花,______部分被害虫吃掉后将不能结出果实?
A.花被 | B.雄蕊 | C.雌蕊 | D.蜜腺 |
(4)绿色植物的受精过程依次是
a.精子与卵细胞结合 b.花粉管进入子房 c.花粉管进入胚珠
d.花粉萌发长出花粉管 e.花粉管末端破裂放出精子

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

