Life Through Time: Geologic Time and Life

The video explains how Earth's 4.6 billion-year history is organized into geologic time, divided into eras, periods, and epochs. These segments are based on significant life changes, such as the Mesozoic Era, known as the age of reptiles, and the Cenozoic Era, known as the age of mammals.

What is the purpose of dividing Earth's history into segments?

• To make it easier for scientists to organize events

• To confuse students

• To create more jobs for historians

• To make history books longer

What are the largest units of time in the geologic time scale called?

• Centuries

• Eras

• Periods

• Epochs

How many major eras are there in the geologic time scale?

• Three

• Four

• Five

• Six

What are periods divided into?

• Decades

• Centuries

• Epochs

• Millennia

Which era is known as the age of mammals?

• Mesozoic Era

• Proterozoic Era

• Paleozoic Era

• Cenozoic Era