11.2 Gas Exchange Quiz

State which of these is the waste gas that is expelled from the body during exhalation.

• Sulfur Dioxide

• Oxygen

• Carbon Monoxide

• Carbon Dioxide

Answer explanation

The waste gas expelled during exhalation is carbon dioxide. It is a byproduct of cellular respiration, while oxygen is inhaled. Sulfur dioxide and carbon monoxide are not produced in significant amounts during normal respiration.

Recall the primary function of the respiratory system.

• To ensure each cell receives enough oxygen

• To facilitate the exchange of carbon dioxide and oxygen between the environment and our bodies

• To digest and metabolise foods

• To maintain the body's optimal pH.

Answer explanation

The primary function of the respiratory system is to facilitate the exchange of carbon dioxide and oxygen between the environment and our bodies, ensuring that oxygen is delivered to cells and carbon dioxide is removed.

Identify what structure is indicated by the blue arrow in the picture.

• Abdomen

• Trachea

• Vocal Cords

• Bronchi

Answer explanation

The blue arrow indicates the bronchi, which are the main passageways that branch from the trachea into the lungs. Unlike the abdomen, trachea, or vocal cords, the bronchi specifically refer to these airways.

Recall which of the following causes inhalation.

• The diaphragm contracting

• The diaphragm relaxing

• The intercostal muscles contracting

• The thorax getting smaller

Answer explanation

Inhalation occurs when the diaphragm contracts, creating a vacuum that pulls air into the lungs. The other options do not facilitate inhalation; relaxing the diaphragm or a smaller thorax would lead to exhalation.

In inhaled air, recall if there is a higher concentration of carbon dioxide or oxygen.

• Oxygen

• Carbon Dioxide

Answer explanation

Inhaled air contains a higher concentration of oxygen (about 21%) compared to carbon dioxide (about 0.04%). Therefore, the correct answer is oxygen.

When you breathe, your lungs take in ___ and remove ___.

• air/oxygen

• oxygen/carbon dioxide

• carbon dioxide/waste

• waste/air

Answer explanation

When you breathe, your lungs take in oxygen from the air and remove carbon dioxide, a waste product of metabolism. Thus, the correct answer is oxygen/carbon dioxide.

Tags

NGSS.MS-LS2-3

The air sacs that are covered with capillaries where gas exchange takes place

• bronchi

• lungs

• oxygen

• alveoli

Answer explanation

The alveoli are tiny air sacs in the lungs covered with capillaries where gas exchange occurs. They facilitate the transfer of oxygen and carbon dioxide between the air and the bloodstream, making them essential for respiration.

What is the site of gas exchange?

• alveoli

• bronchus

• nose

• trachea

Answer explanation

The alveoli are tiny air sacs in the lungs where gas exchange occurs. They allow oxygen to enter the blood and carbon dioxide to be expelled, making them the primary site for this essential process.

What is the name of two main branches from the trachea (one to each lung)?

• bronchi

• alveoli

• capillaries

• bronchioles

Answer explanation

The two main branches from the trachea that lead to each lung are called bronchi. Alveoli are tiny air sacs, capillaries are small blood vessels, and bronchioles are smaller branches of the bronchi.

Given the following structures:

1. alveoli

2. bronchi

3. bronchioles

Which of the following is the correct order in which air would flow after inhalation?

• 1,2,3

• 2,1,3

• 2,3,1

• 3,2,1

Answer explanation

Air flows from the bronchi (2) to the bronchioles (3) and finally reaches the alveoli (1) for gas exchange. Therefore, the correct order is 2, 3, 1.