Internal fertilization is an adaptation to life in a terrestrial environment 體內(nèi)受精是對陸地生活環(huán)境的一種適應(yīng)。
Internal fertilization takes place in the seed plants and some clubmosses and ferns , often by means of a pollen tube 種子植物、某些石松和蕨類植物依賴于花粉管完成體內(nèi)受精。
百科解釋
Fertilization which takes place inside the female body is called internal fertilization. Internal fertilization in animals is done through copulation, which involves the insertion of the penis or other intromittent organ into the vagina (in most mammals) or to the cloaca in monotremes, most reptiles, some birds, the disappeared dinosaurs and some fish, as well as in other non-vertebrate animals.