Question

Which group of autotrophic monerans played significant role in the evolution of aerobic forms of life?

• A. Mycoplasma
• B. Cyanobacteria
• C. Archaebacteria
• D. Actinomycetes

Answer 1

The correct option is B Cyanobacteria

• Photosynthesis is the only significant solar energy storage process on Earth and is the source of all of our food and most of our energy resources.
• There is suggestive evidence that photosynthetic organisms were present approximately 3.2 to 3.5 billion years ago, in the form of stromatolites, layered structures similar to forms that are produced by some modern cyanobacteria, as well as numerous microfossils that have been interpreted as arising from phototrophs.
• The origin of oxygenic photosynthesis in Cyanobacteria led to the rise of oxygen on Earth 2.3 billion years ago, profoundly altering the course of evolution by facilitating the development of aerobic respiration and complex multicellular life.
• The phylogenetic relationships of these prokaryotes suggest that the evolution of aerobic respiration likely occurred multiple times.
  

So the correct option is 'cyanobacteria'.