A.睾丸和卵巢是产生生殖细胞和分泌性激素的器官 |
B.扦插、嫁接、组织培养等具有保持亲本的遗传特性和繁育速度快的特点 |
C.青蛙的发育过程经过受精卵、蝌蚪、幼蛙、成蛙四个时期,属于完全变态发育 |
D.鸟卵的胚盘含细胞核,是将来孵化成雏鸟的重要结构 |

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

