研究人员发现，惯称「四足动物（tetrapods）的所有四肢脊椎动物均无这两个基因。 如果在胚胎发育过程中以手术闭锁这两个基因，斑马鱼将只会发育出缺乏骨质尖刺的短鳍。
基于75个网页-相关网页
N any vertebrate that has four limbs 四足动物
Where children once scrambled over rocks to explore haunted caves, now they climb on cement tetrapods.
昔日孩童们攀爬岩石、探索闹鬼岩洞的地方，现如今已变成只能供他们爬楼梯的水泥四角物了。
Many primitive lineages went extinct as sharks and bony fish became masters of the waters and tetrapods, the four-legged animals that eventually evolved into dinosaurs and mammals, conquered the land.
许多原始生物灭绝，鲨鱼和硬骨鱼成为水域的主人，四足动物最终进化成了恐龙和哺乳动物，征服了陆地。
应用推荐