
(1)图④中“Nc”、“Mgs”和“Int”分别标注的结构是:( )
A.珠被、珠心、子房壁 | B.子房壁、大孢子、珠被 |
C.珠心、大孢子、珠被 | D.珠被、大孢子、子房壁 |
A.卵细胞8,助细胞8 | B.助细胞8、反足细胞16 |
C.卵细胞8,助细胞16 | D.助细胞8、反足细胞24 |
A.胚乳细胞的染色体数目是24 | B.胚乳细胞的染色体数目是36 |
C.胚乳细胞的染色体数目是40 | D.胚乳细胞的染色体数目是16 |

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

