Practice question

Commitment to a lineage proceeds stepwise, with specification representing earliest reversible phase. During this stage, cells develop preferential differentiation tendency when cultured in neutral medium devoid of instructive signals, reflecting initial activation of lineage-specific transcription factors while chromatin remains plastic and receptors still expressed. If transplanted into different embryonic environment, specified cells can still be respecified. Determination follows as irreversible fixation after sustained signaling and epigenetic modifications including autoregulatory loops and histone modifications. Differentiation and morphogenesis execute committed programs. Therefore specification logically precedes determination as labile bias rather than locked fate.