Question

Read the given statements about algae and select the correct option.
I. Plant body is thalloid.
II. They are largely aquatic.
III. Reproduction occurs by vegetative, asexual and sexual methods.
IV. Chlamydomonas, Volvox and Ulothrix are the multicellular algae.

A. Statement I and II are true.
B. Statements II and III are true.
C. Statements I, II and III are true.
D. All statements are true.

Answer 1

Hint: Algae refers to an enormous and varied group of organisms that are eukaryotic in origin. Algae can be a single celled organism (unicellular) or multicellular. Their plant body is not well differentiated into roots, stems and leaves. They undergo a haploid life cycle for their development.

Complete answer:
Algae are mostly found in either the marine water or the freshwater habitats means they are majorly aquatic. But, some algae are also found inhabiting in the terrestrial habitats containing moisture. They can be found on the trunks of the tree, moist soil and on rocks that are wet. Their plant body is thalloid means they lie undifferentiated that is no differentiation of the plant body into the stems, roots or the leaves. They undergo reproduction via three modes -sexual, asexual and vegetative modes of reproduction. They occur abundantly in various forms and sizes. They can be microscopic, composed of single cells (unicellular), like the Chlamydomonas. They can also occur in the form of colonies like the Volvox. Moreover, they can occur in the form of filaments for example, Spirogyra and Ulothrix.

So, the correct answer is option “C” that is the Statement I, II and III are correct.

Note:
Algae contains green pigment known as the chlorophyll therefore they can undergo the process of photosynthesis. They can absorb the solar energy from the sun and the atmospheric carbon dioxide from the environment for the production of their biomass. Therefore, the algae are also known as the "self-feeders", they can prepare their own food using the radiant energy as well as the photosynthetic apparatus.