Question

Which of the following is the best definition for carbon dioxide in the context of the respiratory system?

1) A waste product produced by cells during cellular respiration
2) A gas that is inhaled and exhaled during breathing
3) A molecule that carries oxygen in the blood
4) A substance that is released when we exhale

Answer 1

Carbon dioxide is best defined as a waste product produced by cells during cellular respiration within the respiratory system, and it is exhaled (option 1). It plays a crucial role in the regulation of respiration because its accumulation in the blood triggers the urge to breathe.

Step-by-step explanation:

The best definition of carbon dioxide in the context of the respiratory system is that it is a waste product produced by cells during cellular respiration. During this process, cells consume oxygen and produce carbon dioxide (CO2) as a by-product. In the respiratory system, oxygen is inhaled and used for aerobic cellular respiration within the body's cells, while carbon dioxide, the resultant waste product, is exhaled.

Respiratory organs such as the lungs facilitate gas exchange, allowing for the intake of oxygen and the release of carbon dioxide. Indeed, while oxygen intake is critical for producing adenosine triphosphate (ATP)—the energy currency of the cell—it is the accumulation of carbon dioxide that stimulates the urge to breathe. Transported through the bloodstream, CO2 reaches the lungs, where it is ultimately expelled from the body with each exhalation. Thus, carbon dioxide is not only a metabolic waste product but also an essential component in the regulation of respiration.

Hence, the answer is option 1.

Answer 2

Out of the given options, the best definition for carbon dioxide in the context of the respiratory system is A waste product produced by cells during cellular respiration.

The correct option is 1.

Step-by-step explanation:

1.A waste product produced by cells during cellular respiration:

Carbon dioxide (CO2) is a byproduct of cellular respiration, the metabolic process where cells generate energy by breaking down glucose. During this process, cells produce carbon dioxide as a waste product, which is transported via the bloodstream to the lungs for exhalation.

2.A gas that is inhaled and exhaled during breathing:

While breathing involves the intake of oxygen and the release of carbon dioxide, the primary gas exchanged during respiration is oxygen. Carbon dioxide is mainly exhaled during expiration rather than being inhaled.

3.A molecule that carries oxygen in the blood:

In the bloodstream, oxygen is primarily carried by hemoglobin within red blood cells. Carbon dioxide, on the other hand, is transported in the blood mostly in the form of bicarbonate ions or dissolved directly in the plasma.

4.A substance that is released when we exhale:

Carbon dioxide is indeed expelled from the body when we exhale, but it's not solely a substance released during exhalation. It's formed as a result of cellular metabolism and transported through the bloodstream to the lungs for removal during exhalation.

So, the correct option is 1.