Question

Centrosome is found only in
A. Animal cells
B. Plant cells
C. Both A and B
D. None of the above

Answer 1

Hint: A centrosome, or cell center, is a non-membrane organelle, usually consisting of a pair of centrioles embedded in an amorphous pericentriolar material called the centrosphere or kinoplasm. Around the centrosphere there are rays that radiate in all directions and are known as asters or astrosphere.

Complete answer:
Let’s first of all study centrosomes.
Centrosomes, or cell centers, are cytoplasmic areas (often transparent areas) around a centrosome. Also called a microcenter. Centrosomes are located in the center of the cell next to the cytoplasmic nucleus. In cell biology, a centrosome is an organelle that functions as the main microtubule organization (MTOC) center and as a regulator of cell cycle development.
They were discovered by Van Benden (1880) in the cells of several cephalopod parasites, indicating the origin of the aster. T. Boveri described this in detail in 1888. The substance of the centrosome is called kino plasma and consists of two parts. Small objects or centroids. Mass of the peripheral or central sphere.
Function of centrosome:
> The centrosome appears to initiate cell division, and the centriole is involved in the formation of spindles and astral rays of protein molecules linked by S-H bonds. The spindle fibers also consist of microtubules, and these fibers are responsible for the movement of chromosomes during cell division.
> In Metazoa, the centrosome is located outside the nucleus, while in protozoa, the centrosome is located inside the nucleus.
> The centrosome is the region near the nucleus and in the cytoplasm which contains centrioles. It only exists in animal cells. It’s absent in plant cells. therefore it is not a universal cellular component.

Hence, the correct option is (A).

Note:
Cancer cells have more number of centrosomes than the normal centrosome number. They are also aneuploid (they have an unusual number of chromosomes) and given the role of the centrosome in moving chromosomes, it is tempting to believe that the two phenomena are related. The movement of chromosomes in mitosis also involves polymerization and depolymerisation of microtubules.