Vidaara.orgClass 11 · Mathematics
CodeVID-M11-WS
Breathing and Exchange of Gases — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
15 × 1 = 15 marks
1.
Taking in oxygen-rich air and giving out CO₂-rich air is called:
- A.Digestion
- B.Breathing
- C.Circulation
- D.Excretion
2.
The windpipe is also called the:
- A.Larynx
- B.Trachea
- C.Pharynx
- D.Bronchus
3.
The dome-shaped muscle that helps in breathing is the:
- A.Diaphragm
- B.Biceps
- C.Heart
- D.Stomach
4.
Gas exchange in the lungs takes place in the:
- A.Trachea
- B.Alveoli
- C.Larynx
- D.Pharynx
5.
The trachea is kept open by rings of:
- A.Bone
- B.Cartilage
- C.Muscle only
- D.Fat
6.
During inspiration, the chest cavity:
- A.Enlarges
- B.Shrinks
- C.Stays the same
- D.Collapses
7.
Gases move between alveoli and blood by:
- A.Active transport
- B.Diffusion
- C.Osmosis
- D.Filtration
8.
Most oxygen in the blood is carried by:
- A.Plasma
- B.Haemoglobin
- C.Platelets
- D.White cells
9.
Oxygen combined with haemoglobin is called:
- A.Carbaminohaemoglobin
- B.Oxyhaemoglobin
- C.Methaemoglobin
- D.Bicarbonate
10.
Most carbon dioxide is transported as:
- A.Oxyhaemoglobin
- B.Bicarbonate ions
- C.Free bubbles
- D.Glucose
11.
In the tissues, oxyhaemoglobin tends to:
- A.Release oxygen
- B.Pick up more oxygen
- C.Release carbon dioxide only
- D.Do nothing
12.
A disorder with narrowed, swollen airways and wheezing is:
- A.Asthma
- B.Jaundice
- C.Anaemia
- D.Diabetes
13.
Damage to the alveolar walls, often from smoking, is:
- A.Emphysema
- B.Asthma
- C.Pneumonia
- D.Bronchitis
14.
Silicosis and asbestosis are examples of:
- A.Occupational lung diseases
- B.Heart diseases
- C.Skin diseases
- D.Eye diseases
15.
The single biggest avoidable cause of lung damage is:
- A.Drinking water
- B.Smoking
- C.Exercise
- D.Sleeping
Section B — Challenge / Olympiad (2 marks each)
6 × 2 = 12 marks
16.
Oxygen diffuses from the alveoli into the blood because in the alveoli the oxygen level is:
- A.Higher than in the incoming blood
- B.Lower than in the blood
- C.Equal to the blood
- D.Zero
17.
Haemoglobin is well suited to its job because it picks up oxygen where O₂ is ____ and releases it where O₂ is ____.
- A.High; low
- B.Low; high
- C.Zero; zero
- D.Equal; equal
18.
Carbon-monoxide poisoning is dangerous mainly because CO:
- A.Binds haemoglobin more strongly than oxygen does
- B.Adds oxygen to blood
- C.Speeds breathing safely
- D.Has no effect
19.
Emphysema reduces gas exchange chiefly because the breakdown of alveolar walls:
- A.Decreases the surface area for diffusion
- B.Increases haemoglobin
- C.Makes the trachea wider
- D.Adds more alveoli
20.
Breathing rate increases during exercise mainly to:
- A.Supply more oxygen and remove more CO₂
- B.Cool the blood only
- C.Make more haemoglobin
- D.Reduce oxygen need
21.
A worker constantly exposed to fine stone dust without a mask is at risk of:
- A.Silicosis
- B.Jaundice
- C.Anaemia
- D.Tooth decay
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Breathing
- (B) Trachea
- (A) Diaphragm
- (B) Alveoli
- (B) Cartilage
- (A) Enlarges
- (B) Diffusion
- (B) Haemoglobin
- (B) Oxyhaemoglobin
- (B) Bicarbonate ions
- (A) Release oxygen
- (A) Asthma
- (A) Emphysema
- (A) Occupational lung diseases
- (B) Smoking
Section B — Challenge / Olympiad (2 marks each)
- (A) Higher than in the incoming blood
- (A) High; low
- (A) Binds haemoglobin more strongly than oxygen does
- (A) Decreases the surface area for diffusion
- (A) Supply more oxygen and remove more CO₂
- (A) Silicosis
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