[color=#6600cc][b][u]1.受孕 一个精子游向输卵管黏液膜褶内的一个卵子。[/u][/b]
[/color][img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_645d3e31f091645.jpg[/img]
[b][color=#6600cc][u]2.受孕 两个精子钻入一个卵子的壳内[/u]
[/color][/b][img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_60fd4f588a8793c.jpg[/img]
[color=#6600cc][b][u]3.受孕 一个精子的纵切面。遗传物质储存在精子的头部
[/u][/b][/color][img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_2d014c303028624.jpg[/img]
[b][u][color=#6600cc]4.8天后 新孕育的胚胎定位在某最佳位置，并吸附在黏膜上
[/color][/u][/b][img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_3129b43bc60c776.jpg[/img]
[color=#6600cc][u][b]5.2周后 胚胎尚未发育成熟，但我们可以看到大脑内部了[/b][/u][/color]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_f9109e484015004.jpg[/img]
[b][u][color=#6600cc]6.24天后 第一批发育的器官之一心脏开始跳动[/color][/u][/b]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_43ec84310ef9607.jpg[/img]
[color=#6600cc][u][b]7.9周后 V形血管在头骨融汇处发育[/b][/u][/color]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_18170adea391b77.jpg[/img]
[b][u][color=#6600cc]8.20周后 胎儿现在长约20厘米[/color][/u][/b]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_72471bbe509a2ba.jpg[/img]
[b][u][color=#6600cc]9.36周后 子宫现在紧包着胎儿[/color][/u][/b]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_d760ad60e00a6c2.jpg[/img]
[b][u][color=#6600cc]10.36周后 子宫现在紧包着胎儿[/color][/u][/b]
[img]http://bbsattach.uuu9.com/attachment/Day_100415/9_3382271_94a01f8d65fb72d.jpg[/img]
