NEET BIOLOGY

Detailed explanation-1: -A centriole is a cylinder of nine triplets of microtubules, held together by supporting proteins. Centrioles are best known for their role in centrosomes, structures that act as microtubule organizing centers in animal cells.

Detailed explanation-2: -In animal cells, the major microtubule-organizing center is the centrosome, which is located adjacent to the nucleus near the center of interphase (nondividing) cells (Figure 11.39).

Detailed explanation-3: -Animal cells have centrioles, centrosomes (discussed under the cytoskeleton), and lysosomes, whereas plant cells do not.

Detailed explanation-4: -The cytoskeleton of animal cells is one of the most complicated and functionally versatile structures, involved in processes such as endocytosis, cell division, intra-cellular transport, motility, force transmission, reaction to external forces, adhesion and preservation, and adaptation of cell shape.

Detailed explanation-5: -Microtubules appear like small, hollow, round tubes with a diameter of about 24 nanometers. They are made up of a protein, tubulin. Thirteen tubulins link to form a single tube. Microtubules are very dynamic structures, which reveal that they can change quickly.