Answer:
A feedback loop is a biological occurrence where the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
Explanation:
Example, during blood clotting, a cascade of enzymic proteins acitvates each other, leading to the formation of fibrin clot that prevents further blood loss.
D because they are complete systems
Ciliates move (c) using cilia. It is a group of protozoans. Cilia is an organelle of ciliates. It is a hair-like organelle that helps the ciliate move. It is also used in many ways like food gathering. It could even be used to sweep down food to their central channel.
1. A
2. A
3. B
Those are all the answers