Evolution Question 99
99. The first organisms were
[1992]
(a) Chemoautotrophs
(b) Chemoheterotrophs
(c) Autotrophs
(d) Eucaryotes
Show Answer
Answer : b
Hints & Solution
(b) Chemoheterotrophs were first organisms. They were prokaryotic like bacteria, anaerobes, as molecular oxygen was absent. They obtained energy by fermentation of some of the organic molecules present in the broth. Thus they absorbed organic molecules from outside for body building and energy.
- Chemoautotrophs - Organisms that are capable to synthesize organic molecules from inorganic molecules. E.g., Nitrifying bacteria, sulphur reducing bacteria etc.
- Autotrophs are photosynthesizing plants / organisms.
