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- Two polar nuclei fuse before fertilization. 两个极核在双重受精前融合。
- Double fertilization The fusion of one pollen nucleus with the egg to form the zygote and of the other pollen nucleus with a polar nucleus to form the triploid endosperm nucleus. 双受精：指花粉粒中的一个精子与胚珠中的卵细胞结合形成受精卵，另一个精核与极核结合形成三倍体的胚乳核。
- One fuses with the egg cell to form a zygote while the other either degenerates or, in certain angiosperms, fuses with the polar nuclei to give the primary endosperm nucleus. 一个与卵细胞结合形成受精卵，另一个要么退化，要么在某些被子植物中与极核结合形成初生胚乳核。
- Polar nuclei The, usually two, haploid nuclei found midway along the EMBRYOSAC, forming a binucleate central cell.They may fuse to form the diploid definitive nucleus. 极核：通常指两个位于胚囊中间的单倍体核，他们可能融合形成一个二核的中央细胞。
- Polar nucleus theory of economic growth 增长极核理论
- In flowering plants the endosperm tissue is usually triploid, resulting from the fusion of one of the pollen nuclei with the two polar nuclei. 在开花植物中，胚乳组织多为三倍体，由一个花粉核和两个极核融合产生。
- It fuses with the polar nuclei that are moving towards the antipodal cells at the chalazal end. 大量图片显示了雌雄性核融合的详细过程以及多精受精现象。
- The endosperm is usually triploid and develops from the primary endosperm nucleus, the triploid nucleus resulting from the fusion of one of the male gametes from the pollen tube with the polar nuclei in the embryo sac. 胚乳通常是三倍体，由初生胚乳核发育而来，三倍体核来源于花粉管中的雄配子与胚囊中两个极核的融合。
- The two systems of government are polar opposites. 这两种政体正好相反。
- The endosperm, which is derived from two polar nuclei fusing with one sperm, is a triploid tissue whose genetic constitution is more complex than common diploid tissue. 由于胚乳是由雌性的两个极核和雄性的一个精核受精发育而成的三倍体组织,因此胚乳性状的遗传基础要比通常的二倍体农艺性状复杂得多。
- The development of embryo sac is Polygonum type.The two polar nuclei fuse before fertilization and the the three antipodal cells degenerate soon after fertilization. 胚囊发育为蓼型，两只极核于授精前融合，三枚反足细胞于授精作用之后退化。
- The fortress was the nucleus of the ancient city. 这城堡是这座古城的中心。
- The two polar nuclei move from antipodal end to micropylar end before sperm releasing in a gap between egg cell and central cell and subsequently taking off cytoplasm one after another. 两精子释放于卵细胞与中央细胞的间隙后，精子先后脱去细胞质鞘，移向卵核的精核的运动速度快于移向极核的精核；
- Most insect do not live in polar region. 大多数的昆虫不在极地地区生存。
- The protoplasm outside the nucleus of a cell. 细胞质，细胞浆细胞分子外部的细胞质
- Are there any animals in the polar circles? 南极圈和北极圈内有动物存在吗？
- These 1000 books will form the nucleus of the new school library. 这一千本书将构成学校新图书馆藏书的基础。
- Located or found in one of the Polar Regions. 环极的，围绕极地的位于或发现于一个极地区域中的
- The atomic center is the nucleus, and the electronics winds revolve it. 原子的中央是原子核，电子绕着它旋转。
- In spite of vigilance a polar bear escape from the zoo. 尽管警戒很严，北极熊还是逃出了动物园。
