Biology

Respiration and Gas Transport

606 Questions

Respiration and gas transport deal with the physiological mechanisms of breathing, including the role of hemoglobin in oxygen transport and the removal of carbon dioxide from the blood. Questions cover both aerobic and anaerobic processes, along with related phenomena like altitude sickness. This human biology topic is a staple in the science sections of competitive tests.

Oxygen and hemoglobin transportAnaerobic respiration effectsCarbon dioxide removalAltitude sickness causesBreathing rate regulation

Respiration and Gas Transport Questions

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

In external respiration,

  1. Food is broken down and oxygen is absorbed.

  2. Food is broken down and carbon dioxide is produced.

  3. Oxygen is ejected and carbon dioxide is adsorbed.

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

External respiration also known as breathing refers to a process of inhaling oxygen from the air into the lungs and expelling carbon dioxide from the lungs to the air. Exchange of gases both in and out of the blood occurs simultaneously. External respiration is a physical process during which oxygen is taken up by capillaries of lung alveoli and carbon dioxide is released from blood. Internal respiration or tissue respiration/cellular respiration refers to a metabolic process in which oxygen is released to tissues or living cells and carbon dioxide is absorbed by the blood. Once inside the cell the oxygen is used for producing energy in the form of ATP or adenosine triphosphate. Therefore, the correct answer is option D.

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

Chloride shift is concerned with the transport of 

  1. $CO _2$ and $O _2$
  2. $N _2$
  3. $CO _2$
  4. $O _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chloride shift is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate (HCO$ _{3-}$) and chloride (Cl-) across the membrane of the red blood cells (RBCs).
Therefore, the correct answer is option C.

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

Percentage of O$ _2$ present in inhaled air in man is about 

  1. 21%

  2. 78%

  3. 1%

  4. 43%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Inhaled air contains more oxygen used to create energy and less carbon dioxide. Exhaled air which contains more carbon dioxide produced as a waste product of energy production and less oxygen as it has been used in respiration. Inhaled air contains 21% oxygen, 0.04% CO$ _2$ and 79% N$ _2$. Exhaled air contains 16% oxygen, 4% CO$ _2$ and 79% N$ _2$.

Therefore, the correct answer is option A.

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

In man, expired air contains oxygen about 

  1. 4%

  2. 10%

  3. 16%

  4. 20%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Inhaled air contains more oxygen used to create energy and less carbon dioxide. Exhaled air which contains more carbon dioxide produced as a waste product of energy production and less oxygen as it has been used in respiration. Inhaled air contains 21% oxygen, 0.04% CO$ _2$ and 79% N$ _2$. Exhaled air contains 16% oxygen, 4% CO$ _2$ and 79% N$ _2$. 

Therefore, the correct answer is option C.

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

Read the following sentences carefully and select the incorrect one.

  1. During expiration, $pO _2$ of expired air is more than alveolar air but less than atmospheric air
  2. During expiration, $pO _2$ of expired air is less than $pCO _2$ of alveolar air but more than $pCO _2$ of atmospheric air
  3. Sum of partial pressure of all gases at sea level is $760 mm Hg$
  4. The partial pressure of $O _2$ and $CO _2$$ in the systemic veins is same as that in pulomonary vein.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sum of the partial pressure of all gases is 760 mm of Hg.

The partial pressure of oxygen and carbon dioxide is same in systematic vein since they are continuous.
During expiration, $pO _2$ of experience air is less than $pCO _2$ of alveolar air but less than atmospheric air as the atmosphere has a high concentration of oxygen.
During expiration, $pO _2$ of expired air is less than alveolar air and atmospheric air.
So the correct answer is 'During expiration $pO _2$ of expired air is more than alveolar air but less than atmospheric air'.

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

About 30% of CO$ _2$ is transported as 

  1. Carbamino compounds

  2. Bicarbonates of Na and K

  3. Carboxyhaemoglobin

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

Carbon dioxide can bind to plasma proteins or can enter red blood cells and bind to hemoglobin. This form transports about 10 percent of the carbon dioxide. When carbon dioxide binds to hemoglobin, a molecule called carbaminohemoglobin is formed. Binding of carbon dioxide to hemoglobin is reversible. Therefore, when it reaches the lungs, the carbon dioxide can freely dissociate from the hemoglobin and be expelled from the body. About 30% of CO$ _2$ is transported as carbamino haemoglobin. 

Therefore, the correct answer is option A.

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

If the CO$ _2$ concentration in the blood increases, the breathing shall 

  1. Increase

  2. Decrease

  3. Affected

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

What most people don’t know is that it is, in fact, the level of CO$ _2$ rather than oxygen that usually drives breathing rate. Your body’s ability to detect specific concentrations of CO$ _2$ is extremely sensitive. If the level of CO$ _2$ in your blood increases by a mere 10%, your rate of breathing will double. The answer comes from the way CO$ _2$ is transported. Instead of being bound to hemoglobin, the CO$ _2$ mostly just dissolves in your blood. When the CO$ _2$ dissolves, it combines with the water in your blood to form carbonic acid. As this acid builds up, it dramatically decreases the pH of your blood, throwing it out of balance. Your brainstem detects this pH change, and speeds up your breathing rate in order to to get rid of the extra CO$ _2$. 

Therefore, the correct answer is option A.

Multiple choice biology human body and organ system blood pressure circulatory system transportation in animal and plants

Select the statement which correctly describes the particle pressure of gases in inhaled and exhaled air:

  1. The $pO _2$ in alveolar air is lower than $pO _2$ in venous blood
  2. The $pCO _2$ in exhaled air is greater than $pO _2$ in alveolar air
  3. The $pO _2$ in exhaled air is greater than $pCO _2$ in alveolar air
  4. The $pO _2$ in arterial blood s grater than $pO _2$ in alveolar air
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport


Deficiency of oxygen increases the rate of salt absorption

  1. True

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

A deficiency of 0xygen always causes a corresponding decrease in the rate of mineral absorption. It is probably due to the unavailability of ATP. The increased oxygen tension helps in increased uptake of salts. So the given statement is false.

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis
All of the following processes can release ${CO} _{2}$ except

  1. Alcoholic fermentation

  2. Oxidative decarboxylation and Krebs' cycle

  3. Oxidative phosphorylation
  4. Conversion of $\alpha$-ketoglutaric acid to succinic acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The process of oxidative phosphorylation involves the production of ATP by utilizing electrons falling from the hydrogen in glucose to the oxygen in a living cell. It does not lead to the production of carbon dioxide molecules.

Thus, the correct answer is 'Oxidative phosphorylation.'

Multiple choice biology simple nutrients into cells blood and its components components of blood composition of blood

The blood plasma contains a dissolved substance called ________

  1. Serum

  2. fibrinogen

  3. hemoglobin

  4. pulmonary
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Blood plasma in human beings consists of a dissolved substance called as Haemoglobin which consists of a haem complex with globin protein. The main function of haemoglobin is oxygen transport within the body. It also acts as a buffer.
So, the correct answer is, 'Hemoglobin'.