Respiratory System — Homi Bhabha Class 6 Biology MCQs with Solutions
Free Homi Bhabha Class 6 Biology Respiratory System MCQs with step-by-step solutions (10 questions). Part of Human Body Systems. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Respiratory System · easy · theory
Which gas from the air do we mainly take IN when we breathe?
A. Oxygen (O₂) ✓ Correct
B. Hydrogen
C. Nitrogen
D. Carbon dioxide (CO₂)
Solution: Our body needs oxygen (O₂), so we breathe it in from the air.
Q2 — Respiratory System · easy · theory
Which gas do we mainly give OUT when we breathe out?
A. Nitrogen
B. Carbon dioxide (CO₂) ✓ Correct
C. Oxygen (O₂)
D. Helium
Solution: Carbon dioxide (CO₂) is the body’s waste gas, and we breathe it out.
Q3 — Respiratory System · easy · theory
The pair of spongy organs in our chest that we use for breathing are the:
A. lungs ✓ Correct
B. ears
C. liver
D. kidneys
Solution: The two lungs take in air and pass oxygen into the blood.
Q4 — Respiratory System · easy · theory
We normally breathe in air through our:
A. nose ✓ Correct
B. eyes
C. skin
D. ears
Solution: Air enters the body through the nose, which cleans and warms it.
Q5 — Respiratory System · medium · theory
Air travels from the nose down to the lungs through a tube called the:
A. blood vessel
B. food pipe
C. windpipe ✓ Correct
D. backbone
Solution: The windpipe (trachea) carries air from the nose down into the lungs.
Q6 — Respiratory System · medium · theory
The large dome-shaped muscle below the lungs that helps us breathe is the:
A. stomach
B. liver
C. heart
D. diaphragm ✓ Correct
Solution: The diaphragm moves down and up to pull air into the lungs and push it out.
Q7 — Respiratory System · medium · theory
The tiny hairs and sticky mucus inside the nose mainly help to:
A. make the bones strong
B. digest the food
C. pump the blood
D. trap dust and germs from the air ✓ Correct
Solution: The nose hairs and mucus catch dust and germs so cleaner air reaches the lungs.
Q8 — Respiratory System · medium · theory
Inside the lungs, oxygen passes into the blood through tiny balloon-like:
A. teeth
B. muscles
C. bones
D. air sacs ✓ Correct
Solution: The lungs’ tiny air sacs let oxygen move into the blood and carbon dioxide move out.
Q9 — Respiratory System · hard · numerical
A boy breathes 20 times in one minute. How many times does he breathe in 3 minutes?
A. 200
B. 23
C. 60 ✓ Correct
D. 40
Solution: 20 breaths in each minute × 3 minutes = 60 breaths.
Q10 — Respiratory System · hard · theory
Why is it better to breathe in through the nose than through the mouth?
A. The nose adds germs to the air
B. The nose has no use in breathing
C. The nose makes the air colder
D. The nose cleans, warms and moistens the air ✓ Correct
Solution: The nose filters, warms and moistens the air before it reaches the lungs.