Question

Explain cyclosis and in which organism it is absent.

Answer 1

Hint: Cyclosis is also called cytoplasmic streaming or protoplasmic streaming.
Cytoplasmic streaming has been observed and studied in the cells of Chara, a genus of green algae. Cells of Chara can reach lengths of upto 10 cm in length.

Complete Answer:
Cyclosis is the flow of the cytoplasm inside the cell. This flow of cytoplasm is driven by the forces exerted by the cytoskeleton. The process of cytoplasmic streaming or cyclosis performs the important function of speeding up transport of molecules and organelles across the cell. Cyclosis is most commonly observed in large animal and plant cells. These large cells generally have a size greater than 0.1mm. Relatively smaller cells can transport molecules and organelles with the help of diffusion. Diffusion acts as a rapid means of transport for smaller cells but larger cells require cyclosis for an efficient transfer of molecules and organelles.
Important factors in the efficient functioning of cyclosis are temperature and the intracellular pH. The alteration of temperature in the cell results in varying efficiency for the process of cyclosis. The effect of temperature on cyclosis created a linear variance and more dependence at higher temperatures in contrast to lower temperatures.
Cyclosis is absent in eubacterial cells as their cytoplasm has a gel-like consistency.

Note:
Cyclosis in plants can help move the chloroplasts around the plant cell which results in a change in the efficiency of photosynthesis by positioning the chloroplasts at the optimum position for the absorption of light.
The flow of cyclosis in plant cells is usually affected by factors like:
1. pH
2. Exposure to light
3. Temperature.