I know the answer is C, but can anyone please explain why is it C and how is it
ID: 53951 • Letter: I
Question
I know the answer is C, but can anyone please explain why is it C and how is it relate to +/- toxin treatment?
The mechanism of cell crawling in protist species is not well defined. The textbook states that pseudopodia extension involves interactions between actin and myosin (the same molecules that are involved in mammalian muscle contraction). However, prior to the study described below, no one had provided convincing data that actin and myosin were actually involved in cell crawling in protists. Anatomical studies had identified the cytoskeletal protein actin just below the surface of the cell membrane in several species of protist; but physiological studies had failed to show a functional link between actin, myosin, and cell crawling. In a study by N. Poulsen et al. (Diatom gliding is the result of an actin-myosin motility system, Cell Motility and the Cytoskeleton 44 (1999):23-22), researchers tested whether motility in a particular species of diatom involves interactions between actin and myosin.Explanation / Answer
The formation of actin fibers involves continuous polymerization and depolymerization of actin fibers. So actin fibers which are formed from the monomers of actin units are necessary for the movement. The toxin Latrunculin A is disrupting the formation of the actin fibers, which clearly shows that fully formed actin fibers are necessary for the movement in the diatoms. But it is not affecting the actin monomers. When the other cells treated with buffer is not affected shows that actin fiber formation is an important process for the movement in these diatoms.