Wo structures seen in this animal cell are composed of microtubules are produced by the centriole. what are those two structures?

In cell biology a centriole is a cylindrical cellular organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells. A bound pair of centrioles, surrounded by a shapeless mass of dense material, called the pericentriolar material (PCM), makes up a structure called a centrosome.

b. the carbon cycle ensures living things have a source of hydrogen