Meiosis 配子母细胞或孢子母细胞 间期G期 mother cells of interphase Ga 交换 gametes or meiospores 1462n crossing-over 配子或孢子 gametes/plant and fungi meiospores ● interphase S 2e6 C2c×2=46,2n 间期S期 ee 间期G期 前期I metaphase I 14c,2n) 胞质分裂 中期I meiosis anaphase I 26 n+c.n) 后期I telophase II telophaseI (Cn +cn (2c.n 2c.n) (c n+cn 末期工 末期Ⅱ anaphase II后期Ⅱ (c,n+c n) prophase II前期Ⅱ (c n+c n)
Meiosis
Meiosis Prophase I Leptotene-spindle forms. Ga)细线期 )偶线蝴 )租线期 种平每 ()终变蝴 闭中期1 〔)量后期1 映 〔i)衣期1 〔i)们期 0k)约期 ⊙ mD后期口 〔n)术期0 。)四分件 〔)花铅教 图2-3成数分裂和花粉的形成（转弓引自Gits,AJ.Fet al.1999)
➢ Prophase Ⅰ ✓ Leptotene-spindle forms. Meiosis
Meiosis Prophase I Zygotene-homologous chromosomes pair,shorten,and thicken,and form bivalents(pairs of homologous chromosomes) 典 ()细线期 心)偶纹蝴 )租俊期 d)双线期 的平存时 ()终变期 团中期1 〔)早后期1 〔h)埃后期I 华 〔i)衣蝴1 1)中 Ci)门朔 0)前期口 @ 〔m后期· (m)衣蝴0 。)四分件 您图2-3成数分裂和花粉的形成（转弓1自Griffiths,A.J.Feta1.1999)
➢ Prophase Ⅰ ✓ Zygotene-homologous chromosomes pair,shorten,and thicken,and form bivalents (pairs of homologous chromosomes) Meiosis
Meiosis > Prophase I Pachytene-chiasmata begin to form.These are points at which non-homologous chromatids become associated with each other via base pairing.These become points of 'crossing-over'between the chromatids. C细线 b)出线期 i这 w g 〔)终变蝴 四中期 )早后州1 舒华 [)R1 [1)中期 ()农期口 〔。)四分件 4.88 (m后蝴0 〔花粉粒 图2-3成数分裂和花粉的形成（车转弓自,A J.F.et a1.1999)
➢ Prophase Ⅰ ✓ Pachytene-chiasmata begin to form. These are points at which non-homologous chromatids become associated with each other via base pairing.These become points of ‘crossing-over’ between the chromatids. Meiosis
Meiosis Prophase I Diplotene-exchange of genetic material in chiasmata and nucleolar membrane disappears. 凸)偶俊期 心)线期 d)互位期 1 种具作网 线g (e)终变蝴 )中期 〔)早后期 〔h)晚后期1 )前期口 〔1)中 〔i)问期 〔md后期口 〔)衣期0 。)四分体 〔)花箭粒 图2-3成数分裂和花粉的形成（转弓1自Griffiths,A.JF.eta.1999)
➢ Prophase Ⅰ ✓ Diplotene-exchange of genetic material in chiasmata and nucleolar membrane disappears. Meiosis