Biology

Respiration and Gas Exchange

958 Questions

Access a targeted set of questions on respiration and gas exchange for competitive exams. Topics include lung volumes, the mechanism of breathing, and respiratory anatomy. Understanding these physiological processes is essential for scoring well.

Lung volumes and capacitiesBreathing mechanismsRespiratory anatomyGas exchange processes

Respiration and Gas Exchange Questions

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Choose the correct answer from the alternatives given.
Site of gaseous exchange in lungs is:

  1. pulmonary chamber

  2. trachea

  3. bronchioles

  4. alveoli
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Alveoli are tiny balloon shaped structures in the respiratory system. The alveoli are only one cell thick and are surrounded by blood capillaries. This allows the relatively easy passage of oxygen and carbon dioxide (CO2) between the alveoli and the blood. Alveoli are therefore the site of gaseous exchange in the respiratory system. So, the correct option is 'alveoli'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Choose the correct answer from the alternatives given.
Which of the following constitutes the wind pipe, or the upper four inches of the airway?

  1. Trachea

  2. Pharynx

  3. Larynx

  4. Bronchi
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The trachea is also known as the windpipe and is part of the passageway that supplies air to the lungs, it is about 4.5 inches long. The trachea branches into the bronchi that act as the passageways that enter the lungs. The larynx connects the nasal and oropharynx with the trachea and functions in air conduction and vocalization. The pharynx is the part of the throat behind the mouth and nasal cavity. The trachea connects the pharynx and the larynx to the lungs. So, the correct option is 'trachea'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

State whether the following statements are true or false.
Lungs are completely emptied and refilled with fresh air during breathing.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Even after the most forcible expiration possible some amount of air remains in the lungs. This is known as the residual volume and is about 1200 ml. So, the correct option is 'False'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Choose the correct answer from the alternatives given.
In human lungs, gas exchange occurs at the

  1. two bronchi

  2. alveolar sacs

  3. pleural sacs

  4. both (b) and (c)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In humans, gas exchange occurs in the lungs between the alveoli and the capillaries located on the walls of the alveoli. The inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli. So, the correct option is 'alveolar sacs'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

State whether the following statements are true or false.
Gas exchanges continue uninterrupted in lungs even after a forceful expiration.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Even after the most forcible expiration possible some amount of air remains in the lungs. This is known as the residual volume and is about 1200 ml. This keeps the alveoli open as some air is always present inside the lung alveoli even during expiration. So, the correct option is 'true'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Lungs are enclosed in

  1. Perichondrium

  2. Pericardium

  3. Pleural membrane

  4. Peritoneum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Each lung is enclosed by a double-layered serous membrane, called the pleura. The visceral pleura is firmly attached to the surface of the lung. At the hilum, the visceral pleura is continuous with the parietal pleura that lines the wall of the thorax.

So, the option is 'Pleural membrane'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Consider the following statements each with one or two blanks.
(i)    Left lung has _(1) lobes and right lung has (2) lobes.
(ii)   Prawn respires with (3) and insects with (4).
(iii) Amount of air inhaled and exhaled with maximum effort is referred to as the (5) of the lungs.
Fill up the above blanks by selecting the correct option.

  1. (1) - three, (2) - two, (3) - gills (4)-tracheae

  2. (1) - two, (2) - three, (5) - vital capacity

  3. (3) - gills, (4) - tracheae, (5) - tidal volume

  4. (3) - tracheae, (4) - gills, (5) - tidal volume
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Prawn respires with gills (Branchial respiration) and insects respire by tracheae (Tracheal respiration).

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Mammalian lungs have an enormous number of minute alveoli (air sac);This is to allow

  1. more surface area for diffusion of gases

  2. more space for increasing the volume of inspired air

  3. more nerve supply to keep the lungs working

  4. more spongy texture for keeping lung in proper shape.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The number of alveoli in the human lungs has been estimated to be approximately 300 million. This enormous number of alveoli are meant to increase surface area of lungs for diffusion of gases.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Rings of .................... present in trachea, bronchi and bronchioles prevent their collapse when air is not passing through them.

  1. Cartilage

  2. Collagen

  3. Bone

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In humans, trachea is a straight tube extending up to the mid-thoracic cavity, which divides at the level of 5th thoracic vertebra into a right and left primary bronchi. Each bronchi undergoes repeated divisions to form the secondary and tertiary bronchi and bronchioles ending up in very thin terminal bronchioles. The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

In respiration, air passes through

  1. $Pharynx \rightarrow nasal \:cavity \rightarrow larynx \rightarrow trachea \rightarrow bronchi \rightarrow bronchioles$
  2. $Nasal \:cavity\rightarrow Pharynx\rightarrow larynx \rightarrow trachea \rightarrow bronchi\rightarrow bronchioles$
  3. $Larynx \rightarrow nasal \:cavity\rightarrow Pharynx\rightarrow trachea$
  4. $Larynx \rightarrow pharynx \rightarrow trachea \rightarrow lungs$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nasal cavity open into pharynx which is common passage for transfer of food and air. Pharynx leads to larynx which is also called the voice box. Tracheae carry air to lungs and branch into left and right bronchus for entering left and right lungs. Inside lungs each bronchus divides and subdivides into terminal bronchioles.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

In humans the alveoli are the functioning units of external respiration.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Alveoli are an important part of the respiratory system whose function is to exchange oxygen and carbon dioxide molecules to and from the bloodstream. 
  • Alveoli are tiny, balloon-shaped air sacs present at the very end of the respiratory tree and are arranged in clusters throughout the lungs.
  • A typical pair of human lungs contain about 480 million alveoli. Hence, In humans, the alveoli are the functioning units of external respiration.
So, the correct answer is 'True'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Where does exchange of gases ($O _2$ and $CO _2$) take place in our lungs?

  1. Pleura

  2. Bronchi

  3. Alveoli

  4. Trachea
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The primary function of the respiratory system is to exchange oxygen and carbon dioxide. Inhaled oxygen enters the lungs and reaches the alveoli. The layers of cells lining the alveoli and the surrounding capillaries are each only one cell thick and are in very close contact with each other. This barrier between air and blood averages about 1 micron  in thickness. Oxygen passes quickly through this air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.

So the correct option is 'alveoli'.

Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Read the given statements and choose correct answer :-
(i) Initial bronchioles are supported by incomplete cartilagenous rings.
(ii) In human lungs are solid and spongy.
(iii) Alveoli wall contains simple squamous epithelium and white fibrous connective tissue (iv) Lungs are covered by a single layered pleura

  1. Three statements are correct

  2. Three statements are incorrect

  3. Only two statements are correct

  4. None of them
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The lungs are the primary organs of the respiratory system in humans and
they are covered by a double layered pleura. They are a part of the lower respiratory tract that begins at the trachea and branches into the bronchi and bronchioles. In the main bronchi, hyaline cartilage forms an incomplete ring, giving a "D"-shaped appearance.  The respiratory or gas-exchange surface consists of millions of small sacs, or alveoli, lined by a simple squamous epithelium and white fibrous connective tissue. The lungs feel spongy because of the presence of millions of alveoli inside them. So, i, ii and iii statements are correct. 
So, the correct option is 'Three statements are correct'.
Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

The narrowest and most numerous tubes of lungs are called as

  1. Bronchi

  2. Alveoli

  3. Bronchioles

  4. Tertiary bronchi
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The lungs which form the main respiratory system is a pair of spongy, air-filled organs which is located on either side of the chest in the rib cage. The inhaled air passes through the trachea (windpipe) into the lungs through its tubular branches known as bronchi which further divide into numerous smaller tubes known as the bronchioles. 

Multiple choice evs bones skeletal system and muscles assimilation of food components and importance of food

Which of the bone structures protect the lungs in our body?

  1. Rib cage

  2. Skull

  3. Vertebral column

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All human beings respire air through the process of inhalation and exhalation. That is inhaled passes through the entire respiratory tract and reaches the lungs. Lungs are respiratory organs located in the thoracic cavity of our body.  The partial pressure of the air inside the lungs guides the process of inhalation and exhalation. They are surrounded by ribs. Ribs are bones that together form the rib cage in our thorax. The rib cage protects the lungs.

So, option A "Rib cage" is the correct answer.