Question

An elaborate network of filamentous protein tubular structure forming skeleton of cell in cytoplasm are

• A. Thylakoid
• B. Endoplasmic reticulum
• C. Plasmalemma
• D. Microtubules

Answer 1

The correct option is D Microtubules

Cytoskeletal structures are fibrous or fine tubular structures which constitute the supportive structures of the cell. The term cytoskeleton was first coined by Koltzoff in 1928. Cytoskeletal structures are of three types Microtubules, microfilaments and intermediate fibres. The are made up of proteins like tubulin, actin, desmin, myosin etc.

Microtubules are basic structures of spindle apparatus, centrioles, basal bodies, cilia and flagella. They are also present in other cellular structures like sensory hair, nerve processes, sperm tail etc. Microtubules present in cytoplasm provide shape and polarity to cells. They are involved in cell movements, chromosome movements and intracellular transport.