Question

Which of the following algae is typically terrestrial in nature?
A. Lyngbya
B. Fritschiella
C. Volvox
D. Polysiphonia

Answer 1

Hint: The classification of algae is usually based on the pigment present in them, flagellation and their storage products. Algae are mostly aquatic, either marine or freshwater. Only a few algal species live in moist terrestrial habitats like tree trunks, wet rocks, moist soil, etc.

Complete answer:
Option A Lyngbya: This algal species belongs to the genus of filamentous cyanobacteria in which each filament is surrounded by a sheath. These filaments are helpful to them in gliding motility. They may be free-floating or mat-forming and are found in all types of aquatic environments and also on wet rocks, damp soils, etc.
Option A is correct.
Option B Fritschiella: These belong to the family of green algae which are usually aquatic in nature. They can live on moist soil as well so they are known as subaerial. We can call them half living on land and half in water and their terrestrial nature is mainly due to the production of rhizoids.
Option B is not correct.
Option C Volvox: It is fresh water algae. It looks like a green, hollow ball so called as colonial algae. With a diameter of . There are a fixed number of cells in the colony of Volvox ( to ) and it is known as coenobium.
Option C is not correct.
Option D Polysiphonia: these are small upright bushy structures. These are marine in nature with feathery multiaxial structure. These are one of the most common species of red algae.
Option D is not correct.

Therefore, Option A is the correct answer.

Note:
Algae has a lot of economic importance in the food industry. The plant body of algae is thallus (without any differentiated parts like root, stem and leaf). They may be unicellular, filamentous, colonial, parenchymatous or pseudoparenchymatous. Like other aquatic plants their body is covered with mucilage which protects the algae from the decaying effect of water.