Question

A centrosome is
A. A cytoplasmic organelle is present in plant cells
B. A cytoplasmic organelle is present in animal cells
C. A cytoplasmic organelle is present in plant and animal cells
D. A nuclear structure present in animal cells.

Answer 1

Hint: Centrosome helps in maintaining the number of chromosomes during the cell division. The duplication of chromosomes takes place in the G1 phase of the interphase of the cell cycle.

Complete answer: Centrosome is a cell organelle that is made up of two cylindrical structures called centriole that is surrounded by amorphous pericentriolar materials. In a centrosome both the centrioles lie perpendicular to each other and it has an organization like the cartwheel which consist of nine evenly spaced peripheral fibrils of tubulin protein, and each of the fibrils is a triplet.
The centriole’s central part is proteinaceous and is known as the hub, which is connected with tubules with the peripheral triplets by radial spokes made of protein.
The basal body of centrioles is made up of cilia or flagella, and spindle fibers that form spindle apparatus during cell division in animal cells.
Functions of the centrosomes-
> The centrosomes help in the process of cell division.
> The centrosomes regulate the shape of the cell membrane.
> The centrosomes ensure the distribution of centrosomes to each daughter cell in mitosis.
> The centrosome is a cytoplasmic organelle that is present in animal cells.

So, option B is the correct answer.

Note:
The centrosomes are present in the animals and lower plants while absent in higher plants. The dysfunction of the centrosomes can stimulate cancer which is the increase in the levels of instability in chromosomes, however the study lacks evidence.