Explaining Biology on Instagram: "Biology doesn’t have to be confusing or boring. Sometimes, all it takes is a simple visual to make complex concepts finally click. Biological valves are found throughout the human body—inside veins, the heart, and other systems—working silently to ensure blood and fluids flow in the right direction. These valves open when pressure moves forward and close instantly to prevent backflow, protecting the body from serious complications. This quick demonstration shows

Biology Quiz: Test Your Knowledge