Start learning →

AP Intermediate 1st Year Breathing and Exchange of Gases — practice questions

Explore 50 free Breathing and Exchange of Gases questions in AP Intermediate 1st Year Biology. Open each question or exercise to read its content, reference answers and available explanation.

Practise Breathing and Exchange of Gases with Quill →

Breathing and Exchange of Gases questions and exercises with answers

Showing questions 1–30 of 50.

Gas exchange between alveolar air and blood is driven byRead the answer and worked solution →Vital capacity of the lungs is the sum ofRead the answer and worked solution →During quiet inspiration, the diaphragmRead the answer and worked solution →The actual exchange of O₂ and CO₂ between blood and air happens at theRead the answer and worked solution →Which structure belongs to the conducting (not respiratory) zone?Read the answer and worked solution →Insects breathe throughRead the answer and worked solution →Residual volume (RV) isRead the answer and worked solution →Surfactant in the alveoliRead the answer and worked solution →One haemoglobin molecule can carry a maximum of how many oxygen molecules?Read the answer and worked solution →Most CO₂ is transported in the blood asRead the answer and worked solution →The basic respiratory rhythm is generated in theRead the answer and worked solution →Emphysema is most commonly caused byRead the answer and worked solution →Carbon monoxide poisoning is dangerous because CORead the answer and worked solution →Match each part of the airwayRead the answer and worked solution →Inspiration or expiration?Read the answer and worked solution →A sponge has no lungs or gills. It exchanges gases by:Read the answer and worked solution →An earthworm breathes through its:Read the answer and worked solution →A frog can also breathe through its moist skin. This is called:Read the answer and worked solution →The pharynx is a passage shared by:Read the answer and worked solution →The larynx is called the sound box because it helps in:Read the answer and worked solution →While you swallow, a flap covers the glottis so food does not enter the larynx. The flap is the:Read the answer and worked solution →The trachea and bronchi stay open because they are supported by incomplete rings of:Read the answer and worked solution →The tiny thin-walled bags at the end of each terminal bronchiole are the:Read the answer and worked solution →Air enters the lungs when the pressure inside the lungs is:Read the answer and worked solution →External intercostal muscles contract and:Read the answer and worked solution →A healthy adult at rest breathes about ___ times a minute.Read the answer and worked solution →The device that measures the volumes of air moved in breathing is a:Read the answer and worked solution →The air you breathe in or out in one normal breath, about 500 mL, is the:Read the answer and worked solution →After a normal breath you force in extra air. That extra amount is the:Read the answer and worked solution →Gases cross from alveoli to blood mainly by:Read the answer and worked solution →

Worked practice questions

Gas exchange between alveolar air and blood is driven by

  1. active transport requiring ATP
  2. diffusion along partial-pressure gradients
  3. endocytosis
  4. osmosis
Show answer and solution

Correct answer: B. diffusion along partial-pressure gradients

Pure diffusion. O₂ moves from alveolus (high pO₂) to blood (low pO₂) CO₂ moves the opposite way. No energy needed — just gradients across a very thin (~0.5 μm) membrane.

Open this question →

Vital capacity of the lungs is the sum of

  1. TV + IRV
  2. TV + IRV + ERV
  3. TV + ERV + RV
  4. TV + IRV + ERV + RV
Show answer and solution

Correct answer: B. TV + IRV + ERV

VC = TV + IRV + ERV — the maximum air you can expel after the deepest possible inhalation. ~4600 mL in a healthy adult. Total lung capacity includes residual volume too (≈ 5800 mL).

Open this question →

During quiet inspiration, the diaphragm

  1. domes upward into the thorax
  2. flattens downward, increasing thoracic volume
  3. stays still; only ribs move
  4. moves laterally outward
Show answer and solution

Correct answer: B. flattens downward, increasing thoracic volume

The diaphragm is a muscular dome. Contraction flattens it, pulling downward, expanding the thoracic cavity → pressure drops → air flows in. Relaxation domes it back up → air flows out.

Open this question →

How to practise

  1. Choose a Breathing and Exchange of Gases question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

Put it into practice

Continue with Breathing and Exchange of Gases practice for AP Intermediate 1st Year. Read explanations as you go. No signup form needed to start.

Practise Breathing and Exchange of Gases →

More Biology topics

The Living World & Biological ClassificationPhotosynthesis in Higher PlantsAnimal KingdomBody Fluids and CirculationCell Cycle and Cell DivisionLocomotion and MovementNeural Control and Chemical CoordinationPlant Growth and Development