Question

Select the correct combination of the statements (a-d) regarding the characteristics of certain organisms.
(a) Methanogens are archaebacteria, which produce methane in marshy areas.
(b) Nostoc is a filamentous blue-green alga, which fixes atmospheric nitrogen.
(c) Chemosynthetic autotrophic bacteria synthesize cellulose from glucose.
(d) Mycoplasma lacks a cell wall and can survive without oxygen.
The correct statements are
A. (a), (b), (d)
B. (b), (c)
C. (a), (b), (c)
D. (b), (c), (d)

Answer 1

All the bacterias belong to the kingdom Monera. Chemosynthetic autotrophic bacteria use carbon dioxide for the production of their food. As they can produce their own food by chemical reactions using carbon dioxide hence they are named chemosynthetic autotrophic bacteria.

Complete step by step answer: Microorganisms which produce metabolic byproducts as methane in hypoxic conditions are called methanogens. They are commonly found in marshy places, wetland, and are responsible for the marsh gas present in that region. They are also present in the digestive tracts of ruminants which are responsible for the belching of methane content. As methanogen is a single-celled organism it belongs to the archaea group and is known as archaebacteria.
-Nostoc is a cyanobacterium composed of filaments of moniliform cells in a gelatinous sheath and is found in various environments that form colonies. It is used as nitrogen-fixing bacteria in plants which lacks default nitrogen-fixing in them.
-Chemosynthetic autotrophic bacteria belong to the autotrophic bacteria which produce their own food by using chemical energy. Chemosynthetic autotrophic bacteria use carbon as a source of energy for its production of food. Carbon dioxide is an example of a carbon source used by the Chemosynthetic autotrophic bacteria.
-Mycoplasma is a bacteria in which it lacks the cell wall around its cell membrane and hence can survive without the presence of oxygen.
So, the correct option is option A.

Note: Methanogenesis refers to the process of production of methane gas. Nostoc containing protein and vitamin C are consumed as food in many parts of Asia. The smallest bacterial cell yet discovered is the mycoplasma cells. M. pneumonia is mycoplasma which is responsible for the cause of walking pneumonia.