In the polymerization in vitro of actin filaments and microtubules from their subunits, what does the "lag phase" correspond to? nucleation reaching steady state nucleotide exchange atp or gtp hydrolysis treadmilling

Nucleation

Explanation:

The first step of formation of new phase, structure or self-assembly is called as Nucleation.

It is mentioned in the book of Molecular Biology of the Cell that whenever, In-vitro polymerization of micro-tubules and actin filament occur the first step is called nucleation. In other words Lag Phase.

Reference: Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. The Self-Assembly and Dynamic Structure of Cytoskeletal Filaments.

answer; i believe the correct answer to the above question is ( friction)

i think its the first one