Biology Gaseous Exchange MCQs Chapter 13 Class 11

Biology Gaseous Exchange for Entry Tests and FSC Board Exams

Gaseous Exchange is an important chapter in Biology that explains how organisms exchange oxygen and carbon dioxide with their environment. This topic is highly significant for MDCAT, NUMS, AKU, NUST, UET ECAT, and FSC First Year board exams. Key concepts include diffusion, respiration surfaces, breathing mechanism, transport of gases, and structure of human lungs, which are frequently tested in MCQs and conceptual questions.

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Biology Ch 13 Class 11 Gaseous Exchange

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1 / 64

A disease caused by gradual breakdown of the thin walls of alveoli is;

UHS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) Tuberculosis

B) Asthma

C) Emphysema

D) Bronchitis

2 / 64

The infection of lungs is called:

PMC Practice 1
Biology
Gaseous Exchange
Elimination Tool:

A) Emphysema

B) Asthma

C) Pneumonia

D) Bronchitis

3 / 64

_________ respiration is directly involved in the production of energy, necessary for all living activities.

Organismic

Cellular

Both of these

None of thes

4 / 64

The oxygen-binding protein present in skeletal muscles is:

NUMS 2017
Biology
Gaseous Exchange
Elimination Tool:

A) Globin

B) Glycogen

C) Myo Glycogen

D) Myoglobin

5 / 64

Functional units of lungs are called

Alveoli

Air sacs

Parabronchi

None of these

6 / 64

In which of the following are book lungs found?

NUMS 2014
Biology
Gaseous Exchange
Elimination Tool:

A) Clam warm

B) Spider

C) Silverfish

D) Leech

7 / 64

Oxygen is transported by combining with ……….. in Hb.

NUMS 2015
Biology
Gaseous Exchange
Elimination Tool:

A) Nitrogen

B) Iron

D) Hydrogen

C) Carbon

8 / 64

The gas-exchange portion of the human respiratory system is the:

NTS 2016 SMBBMC
Biology
Gaseous Exchange
Elimination Tool:

A) Larynx

B) Trachea

C) Bronchi

D) Alveoli

9 / 64

Carbon dioxide is carried in the blood, mainly as:

NUMS 2015
Biology
Gaseous Exchange
Elimination Tool:

A) Sodium bicarbonate

B) Potassium bicarbonate

C) Carbamino-haemoglobin

D) Dissolved gas in plasma

10 / 64

The blood enters the _____ side of heart

Posterior

Lateral

All possibl

11 / 64

Chest cavity is bounded by ribs and muscles on the sides, while the floor of chest cavity is called:

NUMS 2019 Reconduct
Biology
Gaseous Exchange
Elimination Tool:

A) Pleura

B) Alveoli

C) Chest cage

D) Diaphragm

12 / 64

Diaphragm is a sheet of:

NUMS 2019 Cancelled
Biology
Gaseous Exchange
Elimination Tool:

A) Smooth muscles

B) Cardiac muscles

C) Skeletal muscles

D) All of these

13 / 64

There are ______ stomata per square cm of leaf surface in Tobacco plants.

1200

12000

100,000

1000

14 / 64

Lungs are spongy due to the presence of million of

Air sacs

Alveoli

Bronchioles

Parabronchi

15 / 64

The maximum amount of oxygen which normal human blood absorbs and carries at sea level is how many ml per 100 ml of blood?

PMC Sample 2
Biology
Gaseous Exchange
Elimination Tool:

A) 10

B) 20

C) 30

D) 40

16 / 64

The number of stomata present per cm2 of leaf is:

PMC Sample 2
Biology
Gaseous Exchange
Elimination Tool:

A) Less than 100

B) 1,000 to 60,000

C) One million

D) None of the above

17 / 64

Pharynx leads air into _____ through glottis.

NTS 2012
Biology
Gaseous Exchange
Elimination Tool:

A) Trachea

B) Bronchus

C) Alveoli

E) Larynx

18 / 64

Four plants are present in different environmental conditions. Plant A is present in a warm climate with continuous rainfall, plant B is present in a cool forest, plant C is present in a warm climate with little breeze, while plant D is present in a warm climate with high wind speed. Which one of the above plants will have the highest rate of transpiration?

UHS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) Plant B

B) Plant D

C) Plant A

D) Plant C

19 / 64

During inspiration, the diaphragm:

PMC Practice 3
Biology
Gaseous Exchange
Elimination Tool:

A) Contracts

B) Relaxes

C) Contracts and relaxes

D) None of these options is correct

20 / 64

During inspiration, the space inside the chest cavity is increased due to:

UHS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) The relaxation of the muscles of the diaphragm

B) Relaxation of the external intercostal muscles

D) The contraction of the muscles of the diaphragm

C) Increased pressure

21 / 64

Guard cells function as:

NUMS 2019 Cancelled
Biology
Gaseous Exchange
Elimination Tool:

A) The defense system

B) Multisensory hydraulic valve

C) Hydrostatic pressure

D) All of these

22 / 64

Oxygen contents per liter of air is

10 ml

100 ml

200 ml

100ml

23 / 64

Xerophytes have small thick leaves to;

UHS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) Help them float on water

B) Limit water loss, by increasing the surface area

C) Help them survive in salty environment

D) Limit water loss, by reducing the surface area

24 / 64

The passageways of the respiratory system mucous secreting cells called:

NTS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) Tracheal cells

B) Goblet cells

C) Surfactant cells

D) Pleural cells

25 / 64

The function of respiratory passage, Cilia is to keep the airways clear of:

NTS 2019
Biology
Gaseous Exchange
Elimination Tool:

A) Carbon dioxide

B) Oxygen

C) Dust

D) Carbon Monoxide

26 / 64

Smaller the animals:

NUMS 2014
Biology
Gaseous Exchange
Elimination Tool:

A) More rate of respiration

B) Less the rate of respiration

C) Rate of respiration has nothing to do with the size of animal

D) None of these

27 / 64

Which of the following is not an infection of the lungs/respiratory tract?

NUMS 2015
Biology
Gaseous Exchange
Elimination Tool:

A) Histoplasmosis

B) Tuberculosis

C) Cystic fibrosis

D) None of the given options

28 / 64

During breathing air from Pharynx enters to:

UHS 2018
Biology
Gaseous Exchange
Elimination Tool:

A) Trachea

B) Bronchioles

C) Alveoli

D) Bronchi

29 / 64

Nicotine in tobacco:

NUMS 2014
Biology
Gaseous Exchange
Elimination Tool:

A) Decreases the heart rate

B) Decreases the blood pressure

C) Block the transport or oxygen

D) Paralyzes cells

30 / 64

______ respiration is the process by which cell utilized oxygen and produces CO2

Cellular

Organismic

Both of these

None of these

31 / 64

The respiratory pigment, which has much higher affinity to combine with oxygen is:

NUMS 2016
Biology
Gaseous Exchange
Elimination Tool:

A) Myoglobin

B) Globin

C) Haemoglobin

D) Hemocyanin

32 / 64

Which of the following is the respiratory surface in human beings?

PMC Practice 3
Biology
Gaseous Exchange
Elimination Tool:

A) Lungs

B) Alveoli

D) Alveolar duct

C) Windpipe

33 / 64

Hemoglobin can absorb maximum oxygen at sea level, which is _____ ml/100 ml of blood.

NUMS 2019 Cancelled
Biology
Gaseous Exchange
Elimination Tool:

A) 15

B) 19

C) 19.6

D) 20

34 / 64

Number of spiracles present in cockroach is

35 / 64

Gaseous exchange in plants takes place through the:

NUMS 2020
Biology
Gaseous Exchange
Elimination Tool:

A) Stomata

B) Mesophyll

C) Endoderm

D) Xylem

36 / 64

Vocal cords, which help in voice production are two thin edged fibrous bands, present in:

NUMS 2019 Cancelled
Biology
Gaseous Exchange
Elimination Tool:

A) Glottis

B) Bronchus

C) Larynx

D) Trachea

37 / 64

Haemoglobin carries more oxygen than plasma by:

NTS 2011
Biology
Gaseous Exchange
Elimination Tool:

A) 50 times

B) 20 times

C) 70 times

D) 100 times

38 / 64

When abdomen expands, the number of spiracles open is

39 / 64

Number of spiracles present in the thorax of cockroach is

40 / 64

Parabronchi are open at ______ end/s

Single

Both

Do not have opening

None of these

41 / 64

The most important cause of many of the respiratory disorders is:

NUMS 2019 Cancelled
Biology
Gaseous Exchange
Elimination Tool:

A) Bacterial infection

B) Pollution

C) Smoking

D) Drinking

42 / 64

Water is _____ times viscous than air

1000

5000

8000

43 / 64

The irritant substances of smoke cause smoker’s cough which weakened and bursts:

NUMS 2019 Reconduct
Biology
Gaseous Exchange
Elimination Tool:

A) Bronchi

B) Bronchiole

C) Alveoli

D) Trachea

44 / 64

Of the following, which one is better respiratory medium.

Air

Water

Soil

None of these

45 / 64

Oxygen, released into the atmosphere, comes from:

NUMS 2020
Biology
Gaseous Exchange
Elimination Tool:

A) CO2

B) H2O

C) C6H12O6

D) CO2 and H2O

46 / 64

Gaseous exchange through the skin is known as ______ respiration.

Cuticular

Cutaneous

Skin

Pulmonary

47 / 64

The glycolate produced diffuses into the membrane bounded organelles called

Glyoxisomes

Peroxisomes

Lysosomes

Mitochondria

48 / 64

Which one of the following is a genetic disorder in which abnormally thick mucus is produced in the lungs and other parts of the body?

NUMS 2020
Biology
Gaseous Exchange
Elimination Tool:

A) Lung cancer

B) Chronic bronchitis

C) Cystic fibrosis

D) Emphysema

49 / 64

Chest cavity is bounded by ribs and muscles on the sides, while the floor of chest cavity is called:

NUMS 2015
Biology
Gaseous Exchange
Elimination Tool:

A) Pleura

B) Alveoli

C) Chest cage

D) Diaphragm

50 / 64

Vocal cords are stretched across

Larynx

Pharynx

Golttis

None of these

51 / 64

As pH of blood decreases, H+ ions increases, which combine the proteins part of hemoglobin, to decrease its ability to bind with:

NUMS 2017
Biology
Gaseous Exchange
Elimination Tool:

A) O2

B) CO2

C) CO

D) H2

52 / 64

The structural and functional unit of the lungs is:

PMC Practice 2
Biology
Gaseous Exchange
Elimination Tool:

A) Alveoli

B) Trachea

C) Bronchiole

D) Bronchus

53 / 64

Breathing is considered as a:

PMC Practice 1
Biology
Gaseous Exchange
Elimination Tool:

A) Chemical process

B) Biochemical process

C) Mechanical process

D) Both A and B

54 / 64

As pH of blood decreases, H+ ions increases, which combine the proteins part of hemoglobin, to decrease its ability to bind with:

NUMS 2019 Reconduct
Biology
Gaseous Exchange
Elimination Tool:

A) O2

B) CO2

C) CO

D) H2

55 / 64

In most birds air sacs are _____ in number

56 / 64

The air spaces may comprise upto ______ of total volume of leaf surface.

30%

20%

40%

50%

57 / 64

Lungs are separated from abdominal cavity by a muscular sheath called:

NUMS 2018
Biology
Gaseous Exchange
Elimination Tool:

A) Pleura

B) Rib cage

C) Pericardium

D) Diaphragm

58 / 64

Active site of Rubisco is evolved to bind

CO2

Both of these

H2O

59 / 64

Lungs are covered with double layered thin membranous sac called

Disphragm

Pleura

Pericardium

Rib cage

60 / 64

Booklungs serve the function of respiration in:

NTS 2014
Biology
Gaseous Exchange
Elimination Tool:

A) Scorpion

B) Earthworm

C) Frog

D) Cockroaches

61 / 64

Which of the following correctly explains the structure of myoglobin:

NUMS 2015
Biology
Gaseous Exchange
Elimination Tool:

A) 4 polypeptide chains + 4 heme portions

B) 4 polypeptide chains + 1 heme portions

C) 1 polypeptide chains + 4 heme portions

D) 1 polypeptide chains + 1 heme portions

62 / 64

Thick, waxy & leathery cuticle around leaves is present in which of the following?

PMC Sample 2
Biology
Gaseous Exchange
Elimination Tool:

A) Hydrophytes

C) Halophytes

B) Mesophytes

D) Xerophytes

63 / 64

Most oxygen is transported in the blood:

NUMS 2018
Biology
Gaseous Exchange
Elimination Tool:

A) In the form of bicarbonate ions.

B) Bound to albumin compounds.

C) Dissolved in the plasma.

E) Bound to hemoglobin.

64 / 64

The voice box leads to the trachea which is also called

PMC Practice 1
Biology
Gaseous Exchange
Elimination Tool:

A) Bronchi

B) Bronchioles

C) Windpipe

D) Alveolar duct

Your score is

The average score is 62%

Importance of Gaseous Exchange in Competitive Biology

A clear understanding of Gaseous Exchange helps students explain alveoli structure, gas transport by hemoglobin, breathing movements, and regulation of respiration. Topics such as inhalation and exhalation, respiratory pigments, and effects of smoking are commonly asked in entry tests. Practicing chapter-wise MCQs, diagrams-based questions, and topic-wise exercises enhances accuracy, speed, and conceptual clarity.

Effective Preparation and Practice Resources

An effective preparation strategy for Gaseous Exchange includes regular revision, MCQ practice, and mock testing. Solving past papers and exam-focused questions helps identify frequently tested areas and strengthens weak concepts. PLS Academy provides structured preparation resources that help students master Gaseous Exchange and perform confidently in medical entry tests and FSC board examinations.

JazakAllah.