What are cilia and flagella? How do these structures produce movements? What are some examples of ciliated and flagellated cells in humans?

Answer 1

Cilia are microtubule types that protrude from cells, often involved in moving particles. They are cylindrical and are composed of tube structures wrapped together (picture rods bunched up which extend outward). So these "rods" (microtubules) slide past one another with the help of a motor protein called dynein, which move along the microtubules, aiding in their movement. They also move with the help of energy from ATP.

A major duty of cilia is involved in the lining of tubules. For instance, cilia are involved in respiration of the lungs as they prevent debris and harmful particles from entering the body. They sweep out mucus and dirt from the lungs, allowing for uncontaminated breathing.

Flagella are often found in singular and appear as tails. They aid in cell mobility and function through the power of ATP in eukaryotes which make for a sliding filament system (similar to cilia). The classic example is found within sperm cells, which much migrate freely through the female reproductive tract, to eventually reach the egg. Within bacteria, the energy for movement is derived from proton gradients. There, flagella propel bacteria through the mucus lining of the small intestine.

Cilia and flagella are not vastly different, but quite unique from one another. They're great examples as to how form fits function, which applies to several biological structures among various organisms.

Hope this helps:)