Question

How many of the following are autotrophic prokaryotes.
Aspergellus, Asparagus, Sacharomyces, Nostoc, Funaria, Chlorella, Chlorobium, Nitrobacter, Rhodospirillum, Puccinia, Ocillatoria.
A. 3
B. 4
C. 5
D. 10

Answer 1

Hint: There are two main cell types. They are Prokaryotic cells and Eukaryotic cells. The term autotrophic means the ability to make your own food by the well-known photosynthesis process by using the energy of the sun. The most known prokaryotes are said to be the bacteria. Some autotrophs utilize chemicals for energy purposes instead of light.

Complete answer:
- Aspergellus is a type of fungus. Fungus are said to be heterotrophs. They largely exist as saprophytes.
- Asparagus, Sacharomyces, Nostoc, Funaria, Rhodospirillum, Puccinia and Ocillatoria are also heterotrophic in nature so they all can be eliminated.
- Chlorella can exist as autotroph, heterotrophic and mixotrophic in nature. It is green in autotrophic condition and yellow in heterotrophic condition. Therefore it can be considered.
- Chlorobium, a green sulfur bacteria, are a cluster of autotrophic organisms. They include obligate and facultative autotrophs. This is also considered fulfilling the above condition.
- Nitrobacter is an autotrophic nitrifying bacteria. It does the important function of oxidizing nitrite to nitrate which is a beneficial source for plants.
- Hence, three of them; Chlorella, Nitrobacter and Chlorobium are said to be autotrophic prokaryotes.

Hence, the correct answer is option (A).

Note: There are many types of autotrophic organisms. Best examples of which are algae and phytoplankton. The autotrophs use the sun’s energy to convert water and carbon dioxide into a nutrient source which is glucose. The plants can get energy from the glucose. These organisms are the very first organisms of the food chain and they form the first trophic level because they do not consume other organisms.