Which statement correctly describes the structure of a centriole? a) 3 groups of 9 microtubules b) 4 groups of 6 microtubules c) 6 groups of 4 microtubules d) 9 groups of 3 microtubules

The right answer is D) 9 groups of 3 microtubules

Centrioles are the constituents of a so-called centrosome structure: every animal cell has a centrosome, which is made of two centrioles and which together form a functional unit. A centriole consists of nine triplets inclined microtubules, surrounded by a number of proteins.