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(五)种子1.种子的功能种子是开花植物的基本繁殖器官,它里面包含着一个幼小雏形的休眠植物叫做胚,并且含有大量供胚萌发生长所需用的养料,因此多数植物的种子也成为人类食料的主要来源。2.种子的形成雌蕊经过受精以后,胚珠就渐渐发育而形成种子,任何一种植物的成熟种子都包括胚和种皮两部分,有的种子并且含有胚乳,它和胚一同包藏在种皮里面。种子里的胚是由受精卵发育成的,胚乳是由受精的极核发育成的,种
(E) Seed 1. Seed’s function Seed is the basic reproductive organ of a flowering plant. It contains a young embryonic dormant plant called an embryo, and contains a lot of nutrients for embryonic growth, so the seeds of most plants are also Become the main source of human food. 2. Seed formation After the fertilization of the pistil, the ovules develop gradually to form seeds. The mature seeds of any plant include both embryo and seed coat. Some seeds contain endosperm, which is entrapped in the seed coat together with the embryo. . The embryo in the seed is developed from the fertilized egg and the endosperm is developed from the fertilized polar nucleus.