Multiple choice

The first organisms were

  1. Chemoautotrophs

  2. Chemoheterotrophs

  3. Photoautotrophs

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The earliest organisms are widely believed to have been chemoheterotrophs, which obtained energy and nutrients from organic molecules present in the primordial soup. Autotrophs, such as photoautotrophs, evolved later as organic resources became scarce.

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