The Figure Above Shows the Geological Times Scale

question 30

Multiple Choice

The figure above shows the geological times scale. The Earth's atmosphere has been oxygen rich for

• A)about 500 million years.
• B)its entire history.
• C)about 2 billion years.
• D)a few million years.

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Definitions:

Thoracic Cage

The thoracic cage, also known as the rib cage, is a skeleton structure that encloses the thoracic cavity, protecting the heart and lungs.

Pectoral Girdle

The skeletal framework that provides attachment for the upper limbs to the axial skeleton, consisting of the scapulae and clavicles.

Upper Abdominal Organs

Organs located in the upper portion of the abdomen, including the stomach, liver, gallbladder, spleen, and pancreas.

Lateral Projections

Outward extensions or parts of a structure, often used to describe anatomical features that extend to the sides of the body or body parts.