What were some of the earliest forms of life on Earth?

• A. Multicellular plants
• B. Prokaryotic microorganisms
• C. Mammals
• D. Insects

Answer: (B)

Verified step by step guidance

1. Begin by understanding the timeline of Earth's history. The Earth is approximately 4.5 billion years old, and life is believed to have started around 3.5 billion years ago.
2. Recognize that the earliest forms of life were simple and unicellular. These organisms are known as prokaryotes, which include bacteria and archaea.
3. Prokaryotic microorganisms are characterized by the absence of a nucleus and other membrane-bound organelles. They are simpler than eukaryotic cells, which evolved later.
4. Multicellular plants, mammals, and insects evolved much later in Earth's history. Multicellular organisms require more complex cellular structures and processes, which took billions of years to develop.
5. Understand that the evolution of life on Earth progressed from simple prokaryotic microorganisms to more complex eukaryotic cells, eventually leading to multicellular organisms and the diverse life forms we see today.