Question

“Pond Silk” is common name of-

Answer 1

Hint: Spirogyra is commonly known as water silk or pond silk. Spirogyra is called pond scum as its filaments float on the surface of large masses. It is called by such a name as it continuously secretes mucilage by dissolution of pectin of the outer layer of the cell wall, which is shiny and slimy silk.

Complete Explanation:
Spirogyra is a filamentous green charophyte algae of the Gymnemates order, meaning a chloroplast that is typical of the genus helical or spiral arrangement. Spirogyra is a common alga and belongs to the kingdom of plantae in the world. It is most commonly found in freshwater habitats and it contains over \[400\] Spirogyra species. There are numerous common names like white weed jellyfish, silk, etc.
Spirogyra is very common in relatively clear eutrophic water, developing slimy filamentous green masses. In spring Spirogyra grows under water, but when there is enough sunlight and warmth, they produce large amounts of oxygen, which adheres as bubbles between the tangled filaments. The filamentous masses come to the surface and become visible as slimy green mats. Spirogyra has a cell wall, nucleus, pyrenoid and spiral chloroplasts. As we discussed over here about the general characteristics’ Spirogyra possess, let us know about reproduction. Spirogyra can reproduce both sexually and asexually. In vegetative reproduction, fragmentation takes place. In order to extend the length of new filaments, Spirogyra simply undergoes an intercalary cell division.
Sexual reproduction is of two kinds – the combination of two or more filaments lined side by side is required for scalar for the conjugation. Either partly or over their entire length. The tubular protuberances known as conjugation rods are emitted by one cell each from opposite lined filaments. Vegetative reproduction occurs at lower temperatures.

Note:
Spirogyra cell wall is composed of pectin and cellulose. It has slow running water and shows in running water the mass of long silky filaments; hence it is referred to as silk pool. Spirogyra can be also be commercially used as food around different cultures in the world it is also used as preservatives and used in medicines for cure of rarely diseases.