Final answer:
The statement is false; G-actin bound by thymosin cannot be added to the plus-end of a growing actin filament as thymosin prevents its polymerization.
Step-by-step explanation:
The statement that G-actin bound by thymosin will be added to the plus-end of a growing actin filament is False. G-actin (globular actin) bound to ATP is the form that can be added to the plus-end of a growing actin filament. Thymosin-β4 binds to G-actin to prevent it from assembling into F-actin filaments, therefore, G-actin bound by thymosin is not available for polymerization.
Actin filaments are polar, with a plus (+) end and a minus (-) end, having different rates of growth and shrinkage. Actin filament dynamics are characterized by treadmilling, a process where the filament grows at the plus end and shrinks at the minus end. This polarity and dynamic behavior are crucial for cellular processes such as cell motility, muscle contraction, and cell division.