The Global Extinction Rate Began to Increase

question 5

Multiple Choice

The global extinction rate began to increase

• A) before humans migrated from Africa.
• B) coincided with the development of agriculture.
• C) began when humans became hunter-gatherers.
• D) when the Pleistocene glaciers advanced.
• E) none of the above

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Definitions:

Thoracic Aorta

The section of the aorta that passes through the thorax, supplying blood to the chest wall and thoracic organs.

Cardiac Muscle Fibers

Cardiac muscle fibers are specialized muscle cells in the heart that contract rhythmically to pump blood throughout the body; they are striated and interconnected, facilitating coordinated heart contractions.

Intercalated Discs

Structures in cardiac muscle cells that facilitate the synchronized contraction of the heart by allowing the rapid passage of ions between cells.

Striations

The repeated ridges found in skeletal and cardiac muscle cells due to the organized arrangement of actin and myosin filaments, giving them a striped appearance.