Centriole

Centrioles are paired barrel-shaped organelles in the cytoplasm of animal cells near the nuclear envelope. They play a role in organizing microtubules and are normally found within the centrosome.

• A centrosome contains two centrioles that lie at right angles to each other.
• Each centriole is a cylindrical structure made of <u>nine triplets of microtubules</u>.
• Centrioles are cylindrical structures similar to the basal bodies of cilia and flagella, and are probably precursors of basal bodies.

• If a stem describes a cylinder with "nine triplets of microtubules" -> <u>centriole</u>.
• If the question says "paired barrel-shaped structures inside the centrosome" -> <u>centrioles</u>.
• If a prompt links centrioles to basal bodies/cilia/flagella -> it's pointing at the <u>structural similarity and centriole-to-basal-body connection</u>.