Following the recent scaling theory developed for irreversible adsorption of wormlike chains (WLCs) from a dilute solution, we address several subtle issues regarding the buildup of irreversible adsorption layers. By performing Brownian dynamics simulations for WLCs, we study zipping dynamics of an adsorbing chain and alignment effects due to the interaction with preadsorbed WLCs. The irreversible chemisorption proceeds by zipping on the surface with a typical loop size S-0 The measured loop-size distribution comprises a slowly decreasing small' loop regime and a large loop regime decreasing proportional to s(-5/2), separated by the typical size so. From the computational study of an incoming chain interacting with a preadsorbed one lying flat on the surface, we provide the crossing probability. A strong bias toward crossing (vs alignment and reflection) is observed; and no strong cooperativity of chain alignment is found.