How long ago did multicellular life forms appear in the fossil record?
A)4.5 billion years ago
B)3.8 billion years ago
C)one billion years ago
D)63 million years ago
E)30 million years ago

Question

Quizplus · Accepted Answer

Multicellular life forms appeared in the fossil record around one billion years ago, during the Proterozoic Eon. This marks the transition from unicellular organisms dominating the Earth to more complex organisms consisting of multiple cells. The other answer choices are not accurate: A) 4.5 billion years ago is the age of the Earth and too early for the appearance of complex life forms; B) 3.8 billion years ago is when the first evidence of life on Earth appears in the form of single-celled organisms, but not multicellular; D) 63 million years ago was the time of the most recent mass extinction event, which wiped out the dinosaurs, but not related to the appearance of multicellular life; E) 30 million years ago is relatively recent and not relevant to the appearance of multicellular life. Multicellular life forms appeared in the fossil record approximately one billion years ago. Option A is the age of the Earth, option B is the age of the oldest known fossilized prokaryotic cells, and options D and E are too recent for the appearance of multicellular life forms.

How Long Ago Did Multicellular Life Forms Appear in the Fossil