Cytochalasin is a drug that caps actin filament plus ends, thus preventing actin polymerization. Phalloidin is a drug that binds to and stabilizes actin filaments, preventing actin depolymerization. Even though these drugs have opposite effects on actin polymerization, the addition of either of these drugs instantaneously freezes the cell movements that depends on actin filaments. Explain why drugs that have opposite effects on actin filaments can have a similar effect on cell movements.

The correct answer is - these drugs inhibit both the polymerization and depolymerization of actin.

Explanation:

Cytochalasin is a chemical drug that covers or hides the plus end of the actin filament which inhibits the binding of actin monomers and actin polymerization on another hand the Phalloidin chemical makes the actin filaments stable by attaching to them and inhibits the depolymerization process.

The addition of any of these drugs stops the cell movement which is caused by the actin polymerization and depolymerization which is stoped by these drugs. Cell movement is the process that required both actin polymerization and depolymerization.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.