test 2.2

What is the primary function of the lungs?

• Digestion

• Circulation

• Respiration

• Excretion

Answer explanation

The primary function of the lungs is respiration, which involves the exchange of oxygen and carbon dioxide. This process is essential for providing oxygen to the body and removing waste gases, making respiration the correct answer.

Which gas is essential for human respiration?

• Nitrogen

• Oxygen

• Carbon Dioxide

• Helium

Answer explanation

Oxygen is essential for human respiration as it is required for cellular processes that produce energy. While nitrogen and helium are abundant in the atmosphere, they do not support respiration. Carbon dioxide is a waste product, not a necessity.

What are the pulmonary airways responsible for?

• Transporting blood

• Carrying oxygen to the lungs

• Digesting food

• Filtering waste

Answer explanation

The pulmonary airways are responsible for carrying oxygen to the lungs, allowing for gas exchange. This is essential for respiration, while the other options do not relate to the function of the pulmonary airways.

What is the common term for the thorax?

• Head

• Chest

• Abdomen

• Leg

Answer explanation

The thorax is commonly referred to as the chest. It is the part of the body located between the neck and the abdomen, housing vital organs such as the heart and lungs.

What process involves the exchange of gases in the lungs?

• Digestion

• Photosynthesis

• Respiration

• Circulation

Answer explanation

The process that involves the exchange of gases in the lungs is called respiration. During respiration, oxygen is taken in and carbon dioxide is expelled, which is essential for maintaining life.

What is exhalation?

• Breathing in

• Breathing out

• Digesting food

• Circulating blood

Answer explanation

Exhalation refers to the process of breathing out, where air is expelled from the lungs. This is the opposite of inhalation, which is breathing in. Therefore, the correct answer is 'Breathing out'.

What is inhalation?

• Breathing in

• Breathing out

• Digesting food

• Circulating blood

Answer explanation

Inhalation refers to the process of breathing in air. This is the correct choice, as it specifically describes the act of taking air into the lungs, distinguishing it from exhalation, which is breathing out.

Which of the following is a physical process?

• Respiration

• Photosynthesis

• Digestion

• Evaporation

Answer explanation

Evaporation is a physical process where liquid turns into vapor, while respiration, photosynthesis, and digestion involve biochemical reactions. Therefore, evaporation is the correct choice.

What is the core of the Earth primarily made of?

• Water

• Iron and Nickel

• Sand

• Oxygen

Answer explanation

The core of the Earth is primarily composed of iron and nickel, which are dense metals. This composition is crucial for generating the Earth's magnetic field and contributes to its overall structure.

What is the outermost layer of the Earth called?

• Core

• Mantle

• Crust

• Lithosphere

Answer explanation

The outermost layer of the Earth is called the crust. It is the solid surface layer where we live, distinct from the underlying mantle and core.