The uneven division during the first cell cycle of C. elegans embryogenesis
is illustrated as an example cell biology research.
Image I: anterior (A) <-> posterior (P)
A one-cell C. elegans embryo (right after sperm enters oocyte).
Image II: A <-> P
A 2-cell C. elegans embryo.
Image III: A (with mouth) <-> P (with tail)
An adult C. elegans. In a single-cell embryo, the difference in anterior and posterior is already established. In the 2-cell embryo these differenences are more pronounced (large vs small cells). In the adult worm, there are very distinct structures in the anterior versus posterior.
Basic components in the embryo:
Left: One cell embryo develops into two-cell embryo. Right: matching animation
From the phenomenon and cell polarity animation, polarization can be observed as the generation of two unequal-size daughter cells and the unequal distribution of cellular components in the two daughter cells, e.g.: components on cell membrane (notice the distribution of the purple and orange lines).