Final answer:
Caudal and hb proteins form gradients by establishing concentration and electrical gradients across a membrane. They play a role in creating osmotic gradients, regulating water movement, and crossing the nuclear envelope.
Step-by-step explanation:
Caudal and hb proteins form gradients by establishing concentration and electrical gradients across a membrane. This can occur through the pumping of hydrogen ions across the membrane or the movement of solutes and ions. Caudal and hb proteins play a role in creating osmotic gradients and regulating water movement across membranes. Additionally, they can interact with nuclear pore fibrils to cross the nuclear envelope against a concentration gradient.