poeciloblast

例句：

1. 1. The baby's development depends on the quality of its yolk sac.
   婴儿的发展取决于其卵黄囊的质量。
2. 2. During early development, the yolk sac provides nourishment for the developing embryo.
   在早期发育过程中，卵黄囊为发育中的胚胎提供营养。
3. 3. In some species, the yolk sac can persist into adulthood, providing nutrients to the organism.
   在某些物种中，卵黄囊可以持续到成年期，为生物体提供养分。