Assertion: Eukaryotic cells have the ability to adopt a variety of shapes and carry out directed movements.

Reason: There are three principal types of protein filaments - microfilaments, microtubules and intermediate filaments, which constitute the cytoskeleton.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

A.

If both assertion and reason are true and reason is the correct explanation of assertion.

The cytoskeleton is a fibrous network made or proteins that contributes to the structure and internal organization of eukaryotic cells within the cytoplasm. It is a dynamic structure that maintains cell shape, enables some cell motion (using structures such as flagella and cilia), and plays important roles in both intra-cellular transport (the movement of vesicles and organelles, for example) and cellular division.

The cytoskeleton has three major fibre types: microfilaments made ofactin protein, intermediate filaments made or various kinds of proteins (eg keratin), and microtubules made of tubulin.