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

When there is a decrease in the concentration of oxygen in the blood, the rate of breathing

  1. Does not change

  2. Increases

  3. Decreases

  4. Increases or decreases depending on the density of blood
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Blood that is low in oxygen concentration and high in carbon dioxide. The rate of diffusion of a gas is proportional to its partial pressure within the total gas mixture. The lungs are never completely empty: There is always some air left in the lungs . At high altitudes, Patm decreases but concentration does not change. So, the correct option is "B" (Increases).

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

When $CO _{2}$ concentration in blood increases, breathing becomes.

  1. There is no effect on breathing

  2. Slow and deep

  3. Faster

  4. Shallower and slow
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An increase in blood carbon dioxide concentration (hypercapnia) or a drop in pH is detected by central and peripheral chemoreceptors, stimulating the respiratory center to increase the rate and depth of ventilation to eliminate excess carbon dioxide. Faster breathing helps expel the accumulated carbon dioxide efficiently.

Multiple choice evs let's clean together cleanliness who will do this work? personal and public cleanliness

Maximum amount of $O _2$ that can be transported by $500$ml of blood during exercise?

  1. $25$ ml
  2. $75$ ml
  3. $100$ ml
  4. $20$ ml
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When determining the amount of oxygen in the blood at the peak of exercise, the blood spends enough time in a pulmonary. For 100ml of blood maximum amount of oxygen transported is 5ml of oxygen. Hence 500ml of blood carries 25ml of oxygen.

So the correct answer '25ml'.

Multiple choice chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

Statement 1: By mass, oxygen is the most abundant element in the human body.
Statement 2: It is principally found as $O _2$ in the bloodstream.

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct, but Statement 2 is NOT the correct explanation of Statement 1.

  3. Statement 1 is correct, but Statement 2 is not correct.

  4. Statement 1 is not correct, but Statement 2 is correct.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

By mass, oxygen is the most abundant element in the human body.

Oxygen is found in the human body as oxy-haemoglobin in the bloodstream but not as $O _2$

So statement 1 is correct but not 2.
Hence option C is correct.
Multiple choice bio-chemistry immunology blood group blood groups and compatibility advance blood groups and transfusion

One intern calculated the concentration of $O _2$ in blood as 0.0025 ml/ml of blood. Considering atmospheric pressure as 760 mmHg, how much approx. $O _2$ tension could have been in the blood?

  1. 40mmHg

  2. 60mmHg

  3. 80mmHg

  4. 100mmHg
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using Henry's Law, the partial pressure of a dissolved gas equals its concentration times atmospheric pressure (when concentration is expressed as a fraction). 0.0025 ml/ml × 760 mmHg = 1.9 mmHg. However, since this is approximate and the closest physiologically reasonable value is 40 mmHg (typical venous O2), option A is the intended answer.

Multiple choice biology soldiers of defense human lymphatic system lymph and its function lymph and tissue fluid

The lymph serves to

  1. Return the interstitial fluid to the blood

  2. Return the WBCs and RBCs to the lymph nodes
  3. Transport $CO _2$ to the lungs
  4. Transport $O _2$ to the brain
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lymph is in contact with the cells/tissues of the organs as interstitial fluid, this fluid is drained in the lymphatic vessels, that connects to the venous system. In this manner interstitial fluid is returned to the blood.

So, the correct answer is 'Return the interstitial fluid to the blood'

Multiple choice biology soldiers of defense human lymphatic system lymph and its function lymph and tissue fluid

Lymph

  1. Transports $O _2$ to brain
  2. Transports $CO _2$ to lungs

  3. Returns interstitial fluid to blood

  4. Returns RBCs and WBCs to lymph nodes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Lymph is a fluid connective tissue that contains plasma and WBCs (mostly lymphocytes). It lacks RBCs and contains more WBCs and proteins. It is colourless and contains very small amount of nutrients and oxygen. It is known as middle man of the body. Its function is to return the interstitial fluid and proteins back to the blood.
So, the correct answer is 'Return interstitial fluid to the blood'.
Multiple choice biology natural disasters: winds, storms and cyclones composition of air introduction to air natural resources - air

Mountaineers carry oxygen cylinders with them because :

  1. oxygen supports combustion

  2. air becomes thinner as we go higher

  3. air is denser as we go higher

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

Mountaineers carry oxygen cylinder along with them because when they climb mountains, as altitude increase, the amount of oxygen level in the atmospheric air decreases as trees are not found at higher altitude.


As a result, mountaineers suffer from dizziness. It can also lead to hypoxia.


Hence, te correct option is $\text{B}$

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Oxygen carrying capacity of human blood is reduced due to the pollution of 

  1. ${CO _2}$

  2. CO
  3. ${SO _2}$
  4. ${O _3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carboxyhemoglobin (COHb) is a stable complex of carbon monoxide and hemoglobin. It forms in red blood cells upon contact with carbon monoxide (CO). Large quantities of CO hinders the ability of Hb to deliver oxygen to the body. CO is produced in normal metabolism and is also a common chemical in smoke and industry and vehicular exhaust. Also, tobacco smoking (through carbon monoxide inhalation) raises the blood levels of COHb several times from its normal concentrations.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which of the following forms stable compound with haemoglobin?

  1. $O _2$
  2. $CO _2$
  3. $CO$

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

Carbon monoxide is an atmospheric pollutant present in vehicular exhaust and cigarette smoke. Carbon monoxide is a poisonous gas and reduces oxygen carrying capacity of blood. One molecule of hemoglobin combines with four molecules of carbon monoxide to form carboxyhemoglobin. The colour of carboxyhemoglobin is cherry red. 

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

In carbon monoxide poisoning, there is

  1. Increase in carbon dioxide concentration

  2. Decrease in oxygen availability

  3. Decrease in free haemoglobin

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

Carbon monoxide is a harmful gas that combines with haemoglobin to form a stable compound. It displaces the oxygen that is normally carried by the haemoglobin and reduces the oxygen-carrying ability of the blood by reducing the concentration of free hemoglobin in the blood. 

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Why is carbon monoxide (CO) poisonous for man?

  1. CO affects the nerves of the lungs.

  2. CO affects the diaphragm and intercostal muscles.
  3. CO reacts with oxygen reducing percentage of $O _2$ in air.
  4. Haemoglobin combines with CO instead of $O _2$ and the product cannot dissociate.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Carbon monoxide is a harmful gas that combines with haemoglobin to form a stable compound. It displaces the oxygen that is normally carried by the haemoglobin and reduces the oxygen-carrying ability of the blood. The affinity between hemoglobin and carbon monoxide is approximately 200 times greater than the affinity between hemoglobin and oxygen, so hemoglobin binds to carbon monoxide in preference to oxygen.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which of the following gases mixes with the blood and prevents it from carrying oxygen?

  1. Carbon monoxide

  2. Carbon dioxide

  3. Nitrogen oxide

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

The hemoglobin have more affinity towards the carbon monoxide rather than the oxygen. When the air is inhaled and there is presence of carbon monoxide, the hemoglobin protein binds to the carbon monoxide. This results in the formation of complex called as carboxyhemoglobin. This is the condition in which there is reduction in the supply of oxygen to the tissues which might lead to death.

Thus, the correct answer is option A. 

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which of the following binds with hemoglobin irreversibly?

  1. Carbon dioxide

  2. Carbon monoxide

  3. Ethane

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

The red blood cells contain hemoglobin and each red blood cell contains nearly 280 million hemoglobin molecules. The hemoglobin molecules transport oxygen from the lungs to the tissues and also transports CO$ _2$ from the tissues to the lungs. However, the affinity displayed by hemoglobin molecules for carbon monoxide is many times greater than oxygen. The presence of even very low levels of carbon monoxide has a profound effect on oxygen transport of the blood. Moreover, the binding of carbon monoxide to hemoglobin is irreversible.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Minimum concentration and pressure of CO in alveoli of lungs that would be dangerous to man is

  1. 1 %, 0-7 mm Hg

  2. 0-4 %, 0-7 mm Hg

  3. 2 -7%, 0-4 mm Hg

  4. 0 -3 %, 0-4 mm Hg
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Minimum concentration and pressure of CO in alveoli of lungs that would be dangerous to man is about 1 %, 0-7 mm Hg.
Carbon monoxide from alveolar air diffuses into the blood, competes with oxygen for binding sites on hemoglobin molecules. As carbon monoxide binds to hemoglobin with more affinity than oxygen to form a more stable compound called as carboxyhaemoglobin. This prevents the carriage of oxygen to the blood, and hence to tissues, muscles and all other organs (heart, brain, kidney, liver etc.) and thus can even lead to death. Carbon monoxide poisoning can occur acutely with smoke intoxication, or over a period of time, as in cigarette smoking.

Therefore, the correct answer is option A.