It is invariably found in plants and animal cells. Incorrect.

• Centrioles are present in animal cells but usually absent in higher plants (they lack centrioles, though basal bodies may occur in lower plants).
It has its own DNA. Incorrect.

• Centrioles do not have their own DNA or protein synthesizing machinery (unlike mitochondria and chloroplasts).
It is duplicated in late phase - Incorrect.

• Centrioles duplicate in S phase, not in late .
It is not surrounded by a unit membrane. Correct.

• Centrioles are made of microtubules (9 triplets) and lack a bounding membrane.