Biology

Respiration and Gas Exchange

989 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 evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Organs responsible for breathing in humans and fishes respectively are

  1. Lungs in both

  2. Gills and lungs

  3. Gills in both

  4. Lungs and gills
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Humans have lungs to carry out respiration. Lungs are ingrowths of the body wall and correct to the outside by a series of tubes and small openings.

Whereas grills are convoluted outgrowths containing blood vessels covered by a thin epithelial layer. They increase the surface area for gas exchange in fishes.
So the correct answer is 'Lungs and Gills'. 

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

During which of the following process the diaphragm moves down?

  1. Inspiration

  2. Expiration

  3. Coughing

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

During inspiration, the diaphragm moves down. The contraction of muscle fibers of the diaphragm causes it to become flat and lowered down thereby increasing the volume of the thoracic cavity in anteroposterior axis, in rabbit or lengthwise in man.

So the correct answer is 'Inspiration'

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

The number of times a person breathes in a minute is called as

  1. Inhalation

  2. Respiratory rate

  3. Breathing

  4. Breathing rate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The number of times a person breathes in a minute is called breathing rate. The normal breathing rate for an adult at rest is 12-20 breathes per minute. Breathing rate below and above this range indicates the diseased condition of a person.
So the correct answer is 'Breathing rate'.
Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Dead space is

  1. Upper respiratory tract

  2. Nasal chambers

  3. Alveolar space

  4. Lower respiratory tract
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Dead space of the respiratory system refers to the space in which oxygen ($O _2$) and carbon dioxide ($CO _2$) gasses are not exchanged across the alveolar membrane in the respiratory tract. 
  • Anatomic dead space specifically refers to the volume of air located in the segments of the respiratory tract that are responsible for conducting air to the alveoli and respiratory bronchioles but do not take part in the process of gas exchange itself. 
  • These segments of the respiratory tract include the upper airways, trachea, bronchi, and terminal bronchioles.
So, the correct option is 'Upper respiratory tract'.
Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Rate of breathing is controlled by.

  1. Amount of freely available oxygen

  2. Carbon dioxide in blood

  3. Stress

  4. Muscular functions of the body

  5. All the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The rate of breathing in humans is primarily regulated by the concentration of carbon dioxide in the blood. Chemoreceptors detect changes in CO2 levels and pH, signaling the brain to adjust the ventilation rate to maintain homeostasis.

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Which is true?

  1. Abdominal breathing is predominant in women

  2. Thoracic breathing is predominant in men

  3. Both A and B

  4. Thoracic breathing is predominant in women
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Physiological studies have historically observed that abdominal breathing is more common in women, while thoracic (chest) breathing is more common in men. This is a general anatomical and physiological trend.

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Between breaths the interpleural pressure is approximately _______mm Hg less than atmospheric pressure.

  1. $1$
  2. $4$
  3. $8$
  4. $10$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The intrapleural pressure is normally negative relative to atmospheric pressure to keep the lungs inflated. This pressure is typically about 4 mm Hg lower than the atmospheric pressure between breaths.

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

How the man's respiration will be affected if he ascends a height of 25000 feet

  1. No effect on respiration

  2. Respiratory rate will be decreased

  3. Respiratory rate will be increased

  4. Anything can happen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(c) The partial pressure of $O _2$ will fall drastically along with the fall in barometric pressure, So hypoxia will develop which causes increase in the rate of respiration.





Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Which of the following does not happen in normal quiet exhalation?

  1. Contraction of internal intercostal muscles

  2. Relaxation of phrenic muscles

  3. Relaxation of external intercostal muscles
  4. Both $(2)$ & $(3)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Exhalation is a passive process because of the elastic properties of the lungs. During forced exhalation, internal intercostal muscles which lower the rib cage and decrease thoracic volume while the abdominal muscles push up on the diaphragm which causes the thoracic cavity to contract. 

So the correct answer is 'Relaxation of phrenic muscles and Relaxation of external intercostal muscles'.

Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

The number of time a person breathes in a minute is known as

  1. Respiration rate

  2. Breathing rate

  3. Combustion rate

  4. None of the above
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation
Breathing rate is also called respiratory rate. It is defined as the number of times a person breathes per minute. The normal respiratory rate for an adult at rest is 12 to 20 breathes per minutes. 
So the correct answer is 'Both A and B'.
Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

Ribs moves out during

  1. Inhalation

  2. Exhalation

  3. Coughing

  4. Both A and B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
During inhalation, the ribs move out. This is because the external intercostal muscles are present between ribs. The contraction of these muscles lifts ribs and sternum up and outward causing an increase in the volume of the thoracic cavity in the backwards-forward direction.
So the correct answer is 'Inhalation'.
Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

The average breathing rate of human beings

  1. 15-18 times

  2. 15- 25 times

  3. 10-20 times

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The breathing rate is defined as the no. of times a person breath in one minute. The normal breathing in an adult person is 15 to 18 times per minute. The increase or decease in breathing rate leads to abnormal breathing rate.
So the correct answer is '15-18 times'.
Multiple choice evs respiration in organism human respiration the mechanism of breathing breathing and its movements

During which of the following activity the breathing rate is maximum?

  1. Sleeping

  2. Jumping

  3. Writing

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Breathing rate is maximum in jumping. Because heart rate is faster during jumping which makes quicker pulse. The muscles need more oxygen and more energy at this time. As level of activity increases, breathing rate increases to bring more air into the lungs so that lungs can pump more oxygen into the blood.
So the correct answer is 'Jumping'