Flagella and pili are important parts of bacteria that help them move around and stick to places where they can grow. This is really important for their survival and for making us sick.

Flagella:

• What They Are: Flagella are long, whip-like tails.
• What They Do: They help bacteria swim toward food or away from things that can harm them. This swimming is known as chemotaxis.
• How They Move: Flagella spin like a propeller, which lets bacteria move quickly in liquids.

Pili:

• What They Are: Pili are short, hair-like parts.
• What They Do: They help bacteria stick to surfaces and to the tissues in a host. This is a key step for bacteria to grow and survive.
• Different Types: Some pili, called fimbriae, are mainly for sticking. Others, called sex pili, help bacteria swap genetic material.

In short, flagella help bacteria move, while pili help them attach to places. Together, they give bacteria a better chance to live and cause infections in their host. This is very important for understanding how bacteria behave in medical science.