Question

Cytoskeleton is made up of
A. Cellulose microfibrils
B. Proteinaceous filaments
C. Calcium carbonate granules
D. Callose deposits

Answer 1

Hint: It is a network of fibres that helps the cells in maintaining their shape and to perform functions like division and movement.

Complete answer:
- Cytoskeleton is a system consisting of filaments or fibres which has an interlinking network of proteins filaments and these are mainly present in the cytoplasm of eukaryotic cells(cells containing nucleus). It supports and maintains the shape of cells and helps in their division too.

- There is presence of three types of filaments in the cytoskeleton i.e., actin filaments, microtubules, and intermediate filaments.

- Actin filaments are the smallest one and they are made up of actin protein. It helps to determine the shape of the cell and also helps in the movement of the cell.

- Microtubules are the largest of the filaments and they are made up of tubulin proteins. They play an important role in the movement of daughter chromosomes to form new daughter cells in mitosis.

- Intermediate filaments are the mid-sized ones and these are made from a number of different subunit proteins. These are very stable structures and their function is to position the nucleus within the cell and provide the cell with elastic properties. Therefore, it is clear that cytoskeleton are made up of filaments that are proteinaceous.

Hence, The correct answer is option (B), Proteinaceous filaments.

Note: All the three types of filaments present in the cytoskeleton are made up of proteins as the actin filaments are made up of actin protein, microtubules are made up of tubulin proteins and intermediate filaments are made up of different subunits of proteins. This clearly shows that all the filaments are proteinaceous and cytoskeleton is made up of them.