P5 Science · Chapter 7brightbit.net/worksheets

Respiratory System

Name: ______________________Class: ________Date: ____________Score: ____ / 10

1.
What is the main function of the respiratory system?
(a) To digest food(b) To transport nutrients around the body(c) To take in oxygen and remove carbon dioxide(d) To filter waste from the blood
2.
What is the correct path air takes when you inhale?
(a) Nose → Trachea → Bronchi → Bronchioles → Alveoli(b) Mouth → Bronchi → Trachea → Alveoli(c) Nose → Alveoli → Bronchi → Trachea(d) Trachea → Nose → Bronchi → Alveoli
3.
Where does gas exchange take place in the lungs?
(a) Trachea(b) Bronchi(c) Alveoli(d) Bronchioles
4.
What adaptations make alveoli efficient for gas exchange?
5.
What happens to the diaphragm and rib cage when you inhale?
(a) Diaphragm moves up, rib cage moves down(b) Diaphragm moves down, rib cage moves up and out(c) Both the diaphragm and rib cage move down(d) The diaphragm stays still, rib cage moves in
6.
What is cellular respiration?
(a) Breathing in and out(b) The process by which cells release energy from glucose using oxygen(c) The exchange of gases in the lungs(d) The pumping of blood by the heart
7.
Exhaled air contains more carbon dioxide and water vapour than inhaled air. Explain why.
8.
Smoking damages the cilia in the airways. What problem would this cause?
(a) Less oxygen enters the blood(b) Mucus and particles cannot be cleared from the airways(c) The alveoli produce more oxygen(d) The diaphragm cannot move properly
9.
How does exercise affect the rate of breathing?
10.
Compare inhaled and exhaled air. State TWO differences.

Answer key — P5 Science: Respiratory System

For parents. Step-by-step explanations for every question are free on brightbit.net.

1.(c) To take in oxygen and remove carbon dioxide
2.(a) Nose → Trachea → Bronchi → Bronchioles → Alveoli
3.(c) Alveoli
4.Large surface area (millions of alveoli), thin walls (one cell thick), moist surface, and rich blood supply (capillaries)
5.(b) Diaphragm moves down, rib cage moves up and out
6.(b) The process by which cells release energy from glucose using oxygen
7.Carbon dioxide and water are produced as waste products of cellular respiration in body cells and released into the blood, then expelled through the lungs
8.(b) Mucus and particles cannot be cleared from the airways
9.Exercise increases breathing rate because muscles need more oxygen and produce more carbon dioxide, which must be removed
10.Inhaled air has more oxygen (21%) and less CO2 (0.04%) than exhaled air which has less oxygen (~16%) and more CO2 (~4%)

Free worksheet from BrightBit · more free P1–P6 worksheets at brightbit.net/worksheets

Practise this chapter online with instant feedback

Hints, explanations, streaks and a parent dashboard. Free, no credit card.

P5 Science practice online · All free worksheets

Answer key — P5 Science: Respiratory System

For parents. Step-by-step explanations for every question are free on brightbit.net.

1.(c) To take in oxygen and remove carbon dioxide

2.(a) Nose → Trachea → Bronchi → Bronchioles → Alveoli

3.(c) Alveoli

4.Large surface area (millions of alveoli), thin walls (one cell thick), moist surface, and rich blood supply (capillaries)

5.(b) Diaphragm moves down, rib cage moves up and out

6.(b) The process by which cells release energy from glucose using oxygen

7.Carbon dioxide and water are produced as waste products of cellular respiration in body cells and released into the blood, then expelled through the lungs

8.(b) Mucus and particles cannot be cleared from the airways

9.Exercise increases breathing rate because muscles need more oxygen and produce more carbon dioxide, which must be removed

10.Inhaled air has more oxygen (21%) and less CO2 (0.04%) than exhaled air which has less oxygen (~16%) and more CO2 (~4%)

Free worksheet from BrightBit · more free P1–P6 worksheets at brightbit.net/worksheets