Question

Early organisms in the precambrian era converted ______ to oxygen.

Answer 1

Carbon dioxide to oxygen.
This was the start of the evolution of photosynthesis, where carbon dioxide is broken down to its constituents, and the carbon is used for the synthesis of glucose to be stored in the organism as energy storage.

Hope this helps! :)

Answer 2

Answer:

Early organisms in the precambrian era converted ___Carbon dioxide__ to oxygen.

Explanation:

THE PRECAMBRIAN ERA :

The word Precambrian means before the Cambrian period. Before the formation of oldest rock with having fossils in them this term was used to the whole period of earth's history.

This era gone through number of important changes. One important change is that atmosphere of this era is deprived of Oxygen. All other content of the atmosphere is same as component of air present today but with little water vapours. Early organisms in the precambrian era converts carbon dioxide into oxygen. This oxygen was very less and begins to combine chemically with iron and other elements. This produces great mineral deposits around the world. This is the era from where aerobic respiration organisms start their life cycles.