What is diffusion? Select one option:

• A: The movement of particles from an area of low concentration to an area of high concentration.
• B: The net movement of particles from an area of higher concentration to an area of lower concentration.
• C: The net movement of water from a dilute solution to a concentrated solution.

Gill filaments have many tiny projections called lamellae. Describe how this feature increases the rate of diffusion of oxygen into the blood.

Complete the sentences below about gill regeneration:

• To grow new tissue for the regenerated gill, stem cells divide by the process of $[blank\; 1]$.
• When these stem cells specialize to become functional gill tissue cells, this process is known as $[blank\; 2]$.