What is the most important message delivered by this paper? ced-1 is important for removing cells with surface exposed PS in C. elegans psr-1 is important for removing cells with surface exposed PS in C. elegans tat-1 is important for maintaining PS asymmetry on plasma membrane tat-1 is important for removing cells with surface exposed PS in C. elegans All of the above

tat-1 is a gene that is important for killing the cells that is important for cell corpse engulfment that is important for removing cells with surface exposed PS that is important for keeping PS in the inner leaflet of plasma membrane None of the above

PS is a signal that can induce phagocytosis The fact that live cells with surface exposed PS are randomly engulfed at a low percentage suggests PS is a signal that can induce phagocytosis PS is a signal for apoptotic cells PS is an efficient signal for cell corpse engulfment PS is an efficient signal for cell killing All of the above

Loss of ced-1 can block missing cell phenotype of tat-1(lf) animals, because A ced-1 promotes cell death B ced-1 is important for recognizing surface-exposed PS and phagocytosis of PS-exposed cells C ced-1 is important for PS externalization in tat-1(lf) animals D ced-1 is important for cell corpses engulfment E All of the above

The fact that loss of ced-1 or psr-1 can block missing cell phenotype of tat-1(lf) animals suggests A ced-1 and psr-1 act in the same pathway to promote phagocytosis B ced-1 depends on psr-1 to remove living cells with surface-exposed PS C psr-1 depends on ced-1 to remove living cells with surface-exposed PS D ced-1 is important for clearance of apoptotic cells E None of the above