In early embryogenesis of Caenorhabditis elegans, the first asymmetric cell division produces two distinct blastomeres: the anterior founder cell AB and the posterior stem cell P1. These cells have different developmental roles and specification mechanisms.

The AB cell, a founder cell, exhibits autonomous specification. It has a predetermined developmental fate defined by inherited intrinsic factors, leading to mosaic development. When isolated, AB cells can develop along their specified pathway independently of environmental signals.

In contrast, the P1 cell shows conditional specification. Its developmental fate relies on interactions with neighboring cells and signals; it participates in regulative development. Experimental manipulations reveal that P1’s fate can be influenced by external cues, indicative of flexibility.

Therefore:

• AB cell undergoes autonomous specification leading to mosaic development.

• P1 cell exhibits conditional specification associated with regulative development.

Based on this developmental biology understanding, the appropriate answer to the blastomere specification question is:

(2) P1 cells would show conditional development while AB would show autonomous development.