About 70percent of the Carbon Dioxide (CO₂) in the Atmosphere

question 8

Multiple Choice

About 70percent of the carbon dioxide (CO₂) in the atmosphere comes from _______________; the remainder comes from _________________.

• A) animal flatulence; the use of fossil fuels
• B) photosynthesis; animal flatulence
• C) the use of fossil fuels; the loss of trees and other forest organisms
• D) evaporated water pollutants; agricultural fertilizers

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Definitions:

Sphincter Muscles

Ring-like muscles that constrict or close a bodily passage or orifice to control the passage of substances.

Arterioles

Small blood vessels that branch off from arteries and lead to capillaries, playing a critical role in regulating blood flow and pressure.

Capillary Beds

Networks of capillaries, which are the smallest blood vessels, providing the site for the exchange of oxygen, carbon dioxide, nutrients, and waste between blood and tissues.

Pulmonary Semilunar Valve

A heart valve that prevents backflow of blood from the pulmonary artery into the right ventricle.