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 zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

Which of the following statement(s) is (are) true about respiration?

  1. During inhalation, ribs move inward diaphragm is raised.

  2. In the alveoli, exchange of gases takes place i.e.oxygen from the alveolar air diffuses into blood and carbon dioxide from blood to the alveolar air.

  3. Alveoli increases surface area for exchange of gases.

  4. Both B and C.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The main respiratory surface in humans is the alveoli, which are small air sacs branching off from the bronchioles in the lungs. They are one cell thick and provide a moist and extremely large surface area for gas exchange to occur. Capillaries carrying deoxygenated blood from the pulmonary artery run across the alveoli. Due to the enormous number of alveoli (approximately 300 million in each human lung), the surface area of the lung is very large (75 m2). Having such a large surface area increases the amount of gas that can diffuse into and out of the lungs.

Multiple choice zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

Which of the following is not a characteristic of good respiratory surface?

  1. Thin and moist

  2. Large surface area

  3. Close to oxygen and gas transport.

  4. Thick and dry surface
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The characteristics of a respiratory surface are thin walls, a moist inner surface, a huge combined surface area, a rich blood supply each alveolus is sounded by capillaries. Surfaces which dries out easily, thick and easily damaged are not a characteristic of good respiratory surface. 

Therefore, the correct answer is option D.

Multiple choice evs - i drugs effects of smoking smoking tobacco busy at work - our internal organs

Emphysema is due to intake of

  1. Narcotics

  2. Heroin

  3. Smoking

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

Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath due to over-inflation of the alveoli (air sacs in the lung). It is mainly caused because of Smoking. Shortness of breath is the most common symptom of emphysema. A cough, sometimes caused by the production of mucus, and wheezing may also be symptoms of emphysema. Stopping of smoking and bronchodilating medications along with steroid medications are the treatment of this disease. Hence, the correct answer is option C.

Multiple choice zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

Read the following four statements carefully.
(i) Ventral respiratory group of neurons of medulla oblongata can cause both inspiration and expiration. 
(ii) The part of the respiratory system starting with the external nostrils up to the terminal bronchioles constitutes the respiratory or exchange part of the respiratory system. 
(iii)  During swallowing epiglottis can be covered by a thin elastic cartilaginous flap called glottis to prevent the entry of food into the larynx.
(iv)  Binding of oxygen with haemoglobin is primarily related to partial pressure of $O _{2}$. 
Which of the above two statements are correct? 

  1. (ii) and (iii)

  2. (iii) and (iv)

  3. (i)and(ii)

  4. (i) and (iv)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The part of the respiratory system starting with the external nostrils up to the terminal bronchioles constitutes the conducting part whereas the alveoli and their ducts form the respiratory or exchange part. During swallowing, glottis can be covered by a thin elastic cartilaginous flap called epiglottis to prevent the entry of food into the larynx.

Multiple choice respiration-the energy producing system experiments on photosynthesis cellular respiration introduction to respiration

Which of the following is not a reason that breathing air is easier than breathing water'?

  1. A given volume of air is easier to move across the respiratory organs than the same volume of water.

  2. Air holds more oxygen per unit volume than water.
  3. Water breathers have a difficult time ridding themselves of CO, because $CO _2$ does not dissolve well in water.
  4. Temperature increases affect the $O _2$ content of water more than they do that of air.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carbon dioxide dissolves very well in water, which is actually why water breathers can eliminate CO2 efficiently across their gills. Thus, the statement that CO2 does not dissolve well in water is incorrect, meaning it is not a reason why breathing air is easier than breathing water. In fact, the high solubility of CO2 in water creates challenges for aquatic animals to maintain low internal levels without continuous ventilation.

Multiple choice polyhalogen compounds haloalkanes and haloarenes chemistry

Breathing about 900 parts this substance per million parts of air for a short time cause dizziness heart & fatigue headache is-

  1. Methylene choride

  2. Chloroform

  3. Iodoform

  4. Tetra chlorometane
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chloroform is known to have toxic effects when inhaled, including dizziness, fatigue, and heart issues, even at relatively low concentrations.

Multiple choice biology respiration in plants amphibolic pathway living organisms and energy production life processes in living organisms- part 1

Aerobic respiratory pathway is appropriate termed ___________.

  1. Anabolic

  2. Catabolic

  3. Amphibolic

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

Respiration is called amphibolic because it involves both catabolic processes (breakdown of substrates to release energy) and anabolic processes (use of respiratory intermediates for biosynthesis).

Multiple choice biology respiration in plants amphibolic pathway living organisms and energy production life processes in living organisms- part 1

Aerobic respiratory pathway is appropriately called as

  1. Anabolic

  2. Catbolic

  3. Amphibolic

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

Aerobic respiratory pathway is appropriately called amphibolic pathway. It contains both catabolic and anabolic reactions. The pathway is catabolic because in this pathway, glucose is broken down into carbon dioxide and water. It is also anabolic pathway as energy rich ATP molecule is produced during this pathway. These ATP molecules are later used to carry out various reaction. 

Thus, the correct answer is option C.

Multiple choice biology respiration in plants amphibolic pathway living organisms and energy production life processes in living organisms- part 1
Respiratory Pathway is _______.

  1. Catabolic

  2. Amphibolic

  3. Anabolic

  4. Endergonic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The same respiratory process which acts as a catabolic pathway for respiratory substrates also acts as an anabolic pathway for the synthesis of various intermediary metabolic products and secondary metabolites. The respiratory pathway, therefore, acts both as catabolic as well as an anabolic pathway. Thus, it is better to call it the amphibolic pathway rather than a catabolic pathway alone.

So the correct option is B.

Multiple choice biology respiratory system of human diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Incidence of Emphysema - a respiratory disorder is high in cigarette smokers. In such cases

  1. the bronchioles are found damaged

  2. the alveolar walls are found damaged

  3. the plasma membrane Is found damaged

  4. the respiratory muscles are found damaged.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Emphysema is. a condition of short breath due to breakdown of alveolar wall and'reduction of respiratory area due to smoking.

Multiple choice evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

Which of the following changes occur in diaphragm and intercostal muscles when expiration of air takes place? 

  1. Internal intercostal muscles relax and diaphragm contracts

  2. External intercostal muscles and diaphragm relaxes

  3. Internal intercostal muscles contract and diaphragm relax

  4. External intercostal muscles and diaphragm contract
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • When the internal intercostal muscles contract and diaphragm relax, the ribs move .downward and inward and the diaphragm becomes convex {dome shaped), 
  • thus decreasing the volume of the thoracic cavity and increasing the pressure inside as compared to the atmospheric pressure outside. This will cause the air to move out (expiration).
Multiple choice evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

Consider the following statements each with two blanks. 
(i)    Diaphragm contracts to help in __(1)   while the contraction of abdominal muscles helps in (2). 
(ii). Vital capacity of trained athletes is _(3)__ than that of non-athletes while the vital capacity of non-smokers is (4) than that of smokers. 
(iii) Alveolar P$O {2}$ is  _(5)  than the venous P$O {2}$ while arterial P$O _{2}$ is __(6)_ than the alveolar P$O _{2}$.
Which of the following options gives the correct fill ups for the respective blanks numbers from (1) to (6) in the above statements?

  1. (1)-expiration, (2)-inspiration (5)-higher, (6)-lower

  2. (3)-higher, (4)-lower, (5)-lower, (6)-higher

  3. (1)-inspiration, (2)-forced expiration, (3)-higher, (4)-higher

  4. (1)-expiration, (2)-forced expiration, (5)-higher, (6)-lower
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  (i) Diaphragm contracts to help in (1) inspiration while the contraction of abdominal muscles helps in (2) forced expiration.

(ii) Vital capacity of trained athletes is (3) higher than that of non-athletes while the vital capacity of non-smokers is (4) higher than that of smokers.

(iii) Alveolar PO2 is (5) higher than the venous PO2 while arterial PO2 is (6) lower than the alveolar PO2.

So, the correct answer is '(1)-inspiration, (2)-forced expiration, (3)-higher, (4)-higher'.


Multiple choice evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

Complete the following sentence by selecting the correct option.
The breathing rhythm is generated in the (i) and is influenced by variation in levels of (ii)_ in the blood.

  1. (i)medulla (ii)$CO _{2}$
  2. (i)medulla (ii)$O _{2}$
  3. (i)frontal lobe (ii)$CO _{2}$ and $O _{2}$
  4. (i)frontal lobe (ii)$CO _{2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The basic rhythm of respiration is generated mainly in the dorsal respiratory group in the medulla. Changes in blood carbon dioxide are believed to stimulate the neurons in the chemosensitive area which affect the rhythm centre. $CO _{2}$ acts by forming carbonic acid which dissociates into H+and $HCO _{3}^{-}$. H+ has a direct effect on this. Oxygen does not have a significant direct effect on rhythm centre.
So the correct answer is 'A'.
Multiple choice evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

The most important muscular structure in respiratory system of rabbit is

  1. External intercostal muscles

  2. Internal intercostal muscles

  3. Diaphgram

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

The diaphragm is the dome-shaped sheet of muscle and tendon that serves as the main muscle of respiration and plays a vital role in the breathing process. The diaphragm separates the thoracic cavity containing the heart and lungs, from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.