3.有性繁殖的进化雌雄有别 http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction 有性繁殖起源于120亿年前的单细胞真核生物 衣藻与蕨类的性生活 Fern Life Cycle Mitosis Chlamydomonas Sporophyte Indusium Sorus with many Fronds covering a sporangia Meiosts life cycle sors Spores Fiddlehead Mitosis Rhizome Annulus Young Diplold (2N) Roots Haplold (N) Prothallus Fertilization Sperm Germinating spore E99 Meiosis Rhizoids hollow ertiltrstio cell wall Antheridium Gametophyte 92018/6/14 1 9 3. 有性繁殖的进化-雌雄有别 http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction 有性繁殖起源于 120亿年前 的单细胞真核生物 衣藻与蕨类的性生活