Biology

Respiration and Gas Transport

647 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

Life without oxygen is

  1. impossible

  2. anaerobic

  3. reduction

  4. free from oxidative damage
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Anaerobic respiration is the process by which organisms produce energy in the absence of oxygen.

Multiple choice

The pollutant capable of combining with haemoglobin is

  1. CO

  2. CO2

  3. SO2

  4. NO
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The life threatening effects of carbon monoxide arise from its reversible combination with haemoglobin (Hb) in red blood cells, which causes displacement of oxygen. This results in oxygen starvation or anoxia.

Multiple choice

Which of the following statements is correct?

  1. All animals require a medium for respiration.

  2. In all animals, oxygen is transported by blood.

  3. In all animals, oxygen is taken in from water or air through gills or lungs.

  4. All animals need oxygen for respiration.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All animals require a medium for respiration is a correct respiration.

Multiple choice

In the tissues, high concentrations of carbon dioxide

  1. increases the affinity of haemoglobin to both oxygen and hydrogen

  2. increases the affinity of haemoglobin to oxygen but decreases its affinity to hydrogen

  3. decreases the affinity of haemoglobin to oxygen but increases its affinity to hydrogen

  4. decreases the affinity of haemoglobin to both oxygen and hydrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the tissues, high concentrations of carbon dioxide decreases the affinity of haemoglobin to oxygen but increases its affinity to hydrogen.

Multiple choice

Which of the following processes slows down in the presence of oxygen?

  1. Nitrogen fixation in root nodules of legumes

  2. Respiration in human beings

  3. Burning of fossil fuels

  4. Formation of ozone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxygen is necessary for every form of life and processes which they perform. But, some forms of life, especially bacteria, are poisoned by elemental oxygen. For example, the process of nitrogen fixation by nitrogen-fixing bacteria also takes place in the absence of oxygen and slows down in the presence of oxygen.

Multiple choice

Which of the following statements is incorrect about oxygen?

  1. It is one of the major constituents of air.

  2. It is non-poisonous for anaerobic organisms.

  3. It is an essential component of nucleic acids and lipids.

  4. It is found as oxides of silicon in the earth's crust.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oxygen is poisonous for anaerobic organisms as they work in the absence of oxygen.

Multiple choice

Oxygen is returned to the atmosphere through

  1. combustion

  2. respiration

  3. photosynthesis

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

Oxygen from the atmosphere is used up in three processes, namely combustion, respiration and in the formation of oxides of nitrogen. Oxygen is returned to the atmosphere in only one major process, i.e. photosynthesis. 

Multiple choice

Which of the following statements is/are false?

a. The process by which oxygen reacts with the digested food to form carbon dioxide, water vapour and heat energy is called respiration. b. Charcoal burns in air to produce carbon monoxide. c. Tall chimneys in factories carry harmful gases to the upper layers of air and prevent pollution of air to some extent.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this statement is false. Charcoal burns in air to produce carbon dioxide.

Multiple choice

Mountaineers carry oxygen cylinders on high altitudes because

  1. the volume of water vapours sharply decreases on high altitudes

  2. the volume of carbon dioxide sharply decreases on high altitudes

  3. the volume of nitrogen sharply increases on high altitudes

  4. the volume of oxygen sharply decreases on high altitudes

  5. the volume of carbon dioxide sharply increases on high altitudes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct option. Mountaineers carry oxygen cylinders on high altitudes because the volume of oxygen sharply decreases on high altitudes.

Multiple choice

How does nicotine act in blood?

  1. Stimulates the nervous system

  2. Releases adrenaline

  3. Relaxes the muscles

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

Nicotine is a stimulant that affects the nervous system, triggers the release of adrenaline, and can have varying effects on muscle tone, making all listed options correct.