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

Is breathing and respiration the same?

  1. Yes.

  2. No
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Breathing is the physical act of inhaling and exhaling air. Respiration is the cellular process of using oxygen to break down glucose to release energy.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Which of the following is true regarding expiration?

  1. Exhaled air contains more moisture

  2. Lungs are not completely emptied even after forciful exhalation

  3. Exchange of gases takes place during expiration

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

  • Expiration is a mechanism in which air which contains carbon dioxide release out from the lungs of the body.
  • This air is dry and contains more moisture from the lungs.
  • Lungs can never be empty even after force full expiration some amount of air remains in it known as residual volume.
  • The exchange of gases occurs only at cellular and alveolar site, not in expiration.
So the correct option is 'Both A and B'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

During inspiration, the diaphragm 

  1. Expands

  2. Shows no change

  3. Contracts and flattens

  4. Relaxed to become dome shaped
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During inspiration, the diaphragm contracts and flattens to increase the volume of the the thoracic cavity. This increase in volume leads to a decrease in intra-alveolar pressure, which is a pressure lower than atmospheric pressure and creates the pressure gradient. Due to the gradient the air is from the atmosphere is forced inside the lungs through nasal cavity.

So, the correct answer is 'Contracts and flattens'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Which of the following does not happen during exhalation?

  1. The space in chest cavity decreases

  2. Diaphragm goes up

  3. Air is released

  4. Ribs are pushed upward and outward
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • During exhalation diaphragm relaxes. 
  • The intercoastal muscles also relax.
  • This makes ribs to move down and in.
  • It reduces the volume of the chest cavity and the air is pushed out
So, the correct option is 'Ribs are pushed upward and outward'.
Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

In males, ______ play a role in the movement of respiratory system.

  1. Vertebrae

  2. Sternum

  3. Diaphragm

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

The diaphragm is the muscular organ situated between the thoracic cavity and the abdominal cavity. It contracts and moves downwards due to which the volume in the lungs increases and the air is inhaled. When it relaxes, the volume of the lungs decreases and the air is expelled out.

A. The vertebra is the short bone that makes up the vertebral column.
B. The sternum is the breastbone to which the ribs are attached.
C. The diaphragm is the muscular organ that plays role in the movement of the respiratory system.
D. The liver is the largest gland responsible for various metabolic activities.
Hence, the correct answer is 'Diaphragm'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

The exchange of gases between which of the following is called external respiration?

  1. Lung alveoli and blood capillaries

  2. Lung alveoli and bronchi

  3. The buccal cavity and the external atmosphere

  4. Lung alveoli and pulmonary artery
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When the gaseous exchange occurs due to a difference in the partial pressure of gases between alveoli of lungs and capillaries it is termed as an external exchange as it involves air that ix either inhaled or exhaled from the environment outside the body while when the exchange occurs between capillaries and tissue it is known as the internal exchange.

So the correct option is 'Lung alveoli and blood capillaries'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Which of the following is the correct path of oxygen in humans during inhalation?

  1. Nostrils $\rightarrow$ Nasal Cavity $\rightarrow$ Pharynx $\rightarrow$ Trachea $\rightarrow$ Bronchi $\rightarrow$ Bronchiole $\rightarrow$ Alveoli
  2. Nostrils $\rightarrow$ Nasal Cavity $\rightarrow$ Trachea $\rightarrow$ Pharynx $\rightarrow$ Bronchi $\rightarrow$ Bronchiole $\rightarrow$ Alveoli
  3. Nostrils $\rightarrow$ Nasal Cavity $\rightarrow$ Pharynx $\rightarrow$ Trachea $\rightarrow$ Alveoli $\rightarrow$ Bronchi $\rightarrow$ Bronchiole
  4. Nostrils $\rightarrow$ Nasal Cavity $\rightarrow$ Pharynx $\rightarrow$ Bronchi $\rightarrow$ Trachea $\rightarrow$ Bronchioles $\rightarrow$ Alveoli
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The correct path of oxygen transfer is nostrils - external structures, nasal passage or the nasal cavity then into the pharynx followed by trachea and bronchii to smaller branches called the bronchioles and lastly the alveoli from where it is exchanged into the blood stream with the help of capillaries surrounding the alveoli.
So, the correct answer is Nostrils →→ Nasal Cavity →→ Pharynx →→ Trachea →→ Bronchi →→ Bronchiole →→ Alveoli
Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Inspiration occurs when

  1. Pressure inside lungs is lower than atmospheric pressure

  2. Pressure inside lungs is higher than atmospheric pressure

  3. Pressure inside lungs is same as atmospheric pressure

  4. Pressure has no effect
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Air can be forced to move from one place to another by creating a pressure gradient. In the human body, the contraction of the diaphragm allows it to move down to abdomen cavity slightly. This increases the area in the thoracic cavity and the lungs expand. The intercostal muscles between the ribs also contract and allow the rib bones o come upwards and outward. Due to this, volume in the lungs increases and the pressure decreases. The pressure in the lungs is less than that of atmospheric pressure, so the air is drawn in and inspiration occurs.

Hence, the correct answer is 'Pressure inside lungs is lower than atmospheric pressure'

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

The width of the chest during inspiration :

  1. Decreases

  2. Does not change

  3. Increases

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • When you breathe in, or inhale, your diaphragm contract and move downward. This increases the space in the chest cavity into which lungs expand.
  • The intercostal muscles between ribs also help enlarge the chest cavity.
So, the correct option is 'Does not change'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Which respiratory associated muscles would be contracted if you blow up a balloon?

  1. Diaphragm contracts and internal intercostal muscles would relax

  2. External intercostal muscle contract and phrenic muscles would contract

  3. Internal intercostal and abdominal muscle would contract

  4. Internal intercostal muscles are external intercostal muscles would contract
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Intercostal and abdominal muscle would contract if we blow up a balloon. When this occurs, you are interrupting the natural rhythm of breathing. The inhalation process is blowing up a balloon. As you this movement is facilitated by the contraction of the external intercostal muscles.

So the correct answer is' Internal intercostal and abdominal muscle would contract'.

Multiple choice zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

Volume of thoracic chamber increases in the anteroposterior and dorsoventral axis in the human by?

  1. Contraction of diaphragm and external intercostal muscles

  2. Relaxation of diaphragm and external intercostal muscles

  3. Relaxation of diaphragm and abdominal muscles

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

Volume of thoracic chamber increases in anteroposterior and dorso-ventral axis in human by contraction of diaphragm and external intercostal muscles.