Question

Cyclosis is caused by activity of
A. Microtubules
B. Microfilaments
C. Intermediate filaments
D. All of the above

Answer 1

Hint: Cyclosis is defined as the flow of cytoplasm in the cell due to the forces driven from cytoskeleton. It is also known as protoplasmic streaming or cytoplasmic streaming.

Complete answer:
-Microtubules
Microtubules are defined as the electron microscopic structures found only in the Eukaryotic cellular structures like cilia, flagella, centriole, basal body, astral fibres, spindle fibres, sperm tail, etc.
It is a hollow tubular structure formed of tubulin protein.
The microtubules in the cilia and flagella help in locomotion and feeding.
The microtubules of the neuraxis help in conduction of nerve impulses.
They also control the orientation of cellulose microfibrils in the cell walls of plants.
-Microfilaments
These are electron microscopic long, solid, contractile, and proteinaceous structures. Each microfilament is a solid filament formed of a helical series of globular protein molecules that are generally grouped to form bundles. These are mainly formed of actin like protein.
They form a part of cytoskeleton and help in providing cell shape and mechanical support.
They also help in the cyclosis of the cytoplasm.
Microfilaments of the microvilli help in their movement and absorption of food.
-Intermediate filaments
These are also a type of cytoskeletal structure found in vertebrates and some invertebrates that are formed of helical or coiled proteins.
So, the correct answer is “Option B”.

Note: Cytoplasmic streaming helps in the transport of molecules and organelles inside the cell. It depends upon the temperature and pH of the cell. The cytoplasmic streaming is maximum at neutral pH while it decreases at high and low temperatures.’