CBSE · Class 11 · Geography · The Origin and Evolution of the EarthDuring which geological era did life first appear on Earth in the form of single-celled organisms?
Step-by-Step Solution
Life first appeared in oceans in the form of single-celled blue-green algae and bacteria during the Precambrian era, around 3 billion years ago.
Detailed Options Breakdown
Option : Cenozoic Era
Incorrect choice. This distractor represents a common misunderstanding of the core principles of The Origin and Evolution of the Earth.
Option 1: Mesozoic Era
Incorrect choice. This distractor represents a common misunderstanding of the core principles of The Origin and Evolution of the Earth.
Option 2: Precambrian Era (Correct Answer)
Correct choice. Refer to the step-by-step verified solution guidelines above for details.
Option 3: Paleozoic Era
Incorrect choice. This distractor represents a common misunderstanding of the core principles of The Origin and Evolution of the Earth.
💡 Study Guide: This question tests core syllabus concepts from The Origin and Evolution of the Earth. For formulas, key summaries, and mock exam reference guides, read the full The Origin and Evolution of the Earth Revision Notes.