注册
搜索
全部分类

粮食作物

经济作物

果树

蔬菜

园林花卉

畜牧兽医

牧草杂草

筛选
主题：
尺寸： × 以上 (单位：像素px)
13.21（below） Cross-section of embryo showing different organs and tissues. ×300
13.20（above） Cross-section of embryo showing the formation of mid-gut（arrow）.The ectoderm grows inward from both sides to form the tracheal system，the embryo stretches fur-ther toward dorsal side. ×180
13.19（below） Cross-section of embryo showing further development of the germ layer.The nerve system（n），genital glands（g），dorsal vessel（d）begin to emerge and the embryo starts to close at the dorsal side. ×180
13.18（above） The germ layer stretches upward showing ectoderm（E）and mesoderm（M）. ×250
13.17（below） Cross-section of embryo showing the germ layer which has differentiated from a single cell layer to ectoderm（E）and mesoderm（M）. ×300
13.16（above） Cross-section of embryo showing the invagination of the gastral groove（arrow），and the amnion（Am）surrounding the ventral side of the embryo. ×250
13.15（below） Hatching. ×27
13.14（upper right） The development of the larval body is completed with the caudal portion curled in the egg（arrow）.The head muscles and mouth parts can be seen. ×100
13.13（upper left） The embryo elongates again，the development of all organs and tissues is basically completed.At this stage，fore-，mid-，and hind-gut，nerve system，silk gland，genital glands can be seen. ×100
13.12（lower right） The embryo starts to revolve to look like an“S”，which is called blastokinesis.At this stage，the mid-gut is half-formed（short arrow），and the nerve system can be seen（long arrow）. ×100
13.11（lower left） The embryo shortens further. ×100
13.10（upper right） The embryo shortens and becomes thicker.The fore-gut and hind-gut have been developed and the appendages（arrow）distinctly developed. ×100
13.9（upper left） The embryo elongates to its longest and shows the mesoderm（arrow），stomodeum（S）and proctodeum（P）. ×100
13.8（lower right） The embryo elongates further. ×100
13.7（lower left） The embryo goes on elongation and segmentation begins. ×100
13.6（upper right） The embryo starts to elongate and become narrow. ×80
13.5（upper left） The embryo is formed，but it is still a single cell layer. ×80
13.4（lower right） M ost of the cleavage energids migrate to the periphery to form the blastoderm under the vitellin membrane，the rest remain in the yolk. ×100
  • 1
  • 2
  • 3
  • 4
  • 5
  • >
扫描关注官方微信
友情链接
读者咨询：010-59194945     （署）网出证（京）字第069号
您当前的IP是：