Question

Circulation type of protoplasmic streaming is studied in
a. Staminal hair cell of Tradescantia
b. Hydrilla leaf cells
c. Vallisneria leaf cells
d. Both B and C

Answer 1

Hint: Cytoplasmic streaming 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 cyclosis.

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

> Hydrilla is an aquatic plant with slender and branched stem that are 25 feet long. They have small leaves that are strap-like and pointed and they grow in whorls of four to eight around the stem. The leaves have distinctly saw-toothed margins.

> Vallisneria is a fresh water, submerged aquatic plant that spreads by runners and sometimes forms tall underwater meadows. The leaves in this plat arise from their roots in clusters and have definite raised veins and rounded tips.

> In Tradescantia, the stamens have hairs that consist of filament of cells which are not embedded in the tissue and it becomes easier to observe them under the microscope. So circulation type of protoplasmic streaming is studied in staminal hair cell of Tradescantia.

Hence, the correct answer is option (A).

Note: Bonaventura Corti discovered flow of cytoplasm while observing intermodal cells of algae Nitella and Chara in 1774. He described it as an active intracellular flow that occurs in plant cells.