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

The largest amount of $CO _2$ is transported by the blood as?

  1. $CO _2$ in the plasma
  2. $H _2CO _3$ in the plasma

  3. Bicarbonate ions in plasma

  4. Bicarbonate ions in the erythrocytes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Carbon dioxide produced in the body is transported either in the plasma, in the form of bicarbonate ions or in the form of carbaminohemoglobin. The maximum amount of carbon dioxide is transported in the form of bicarbonate ions formed in the erythrocytes.

So, the correct answer is 'Bicarbonate ions in plasma'.
Multiple choice biology simple nutrients into cells blood and its components components of blood composition of blood

During transport of $CO _2$ , blood does not become acidic due to

  1. Neutralisation of $H _2CO _3$ by $Na _2CO _3$

  2. Absorption of leucoyctes

  3. Blood buffers

  4. Non-accumulation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The bicarbonate buffering system of blood is an important buffer system in the acid-base homeostasis of living things, including humans. As a buffer, it tends to maintain a relatively constant plasma pH and counteract any force that would alter. In this system, carbon dioxide ${CO _{2}}$ combines with water ${H _{2}O}$ to form carbonic acid ${H _{2}CO _{3}}$, which in turn rapidly dissociates to form hydrogen ions ${H^{+}}$ and bicarbonate ${HCO _{3}^{}}$ as shown in the reactions below.
${CO _{2} + H _{2}O \rightleftarrows H _{2}CO _{3} \rightleftarrows HCO _{3}^{-} + H^{+}}$
The carbon dioxide - carbonic acid equilibrium is catalyzed by the enzyme carbonic anhydrase; the carbonic acid - bicarbonate equilibrium is simple proton dissociation/association and needs no catalyst. Any disturbance of the system will be compensated by a shift in the chemical equilibrium.

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

About $97\%$ of oxygen is transported by RBC. The remaining $3\%$ is?

  1. Retained in lungs

  2. Dissolved in plasma and transported

  3. Attached to cell membrane

  4. Inside mitochondria

  5. In peroxisomes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oxygen transport occurs primarily via hemoglobin in RBCs. The small fraction (about 3%) that does not bind to hemoglobin is carried in a dissolved state within the blood plasma.

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

Blood maintains homoestasis in body by

  1. Replenishment of $O _2$ and nutrients, elimination of wastes
  2. Replenishment of $O _2$ and elimination of $CO _2$

  3. Maintenance of sugar level, conversion of amino acids into urea and destruction of worn out RBCs

  4. Maintenance of ion concentration in blood and body fluids by eliminating nitrogenous wastes.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Homeostasis is the maintenance of a stable internal environment. Blood achieves this by delivering oxygen and nutrients to cells while simultaneously removing metabolic waste products like CO2 and urea.

Multiple choice biology simple nutrients into cells blood and its components components of blood composition of blood
Choose the correct option regarding the statements.
1. Plasma constitutes 45% of blood.
2. Albumin is plasma protein involved in osmotic balance.
3. Blood clotting factors are present in blood.
4. Plasma without clotting factors is serum.
5. Minerals are not found in blood.

  1. 1-4 correct, 5 wrong

  2. 1-2 correct, 3, 4, 5 wrong

  3. 2, 3, 4 correct, 1 and 5 wrong

  4. 2 and 4 correct, 1, 3, 5, wrong

  5. 1 and 5 correct, 2, 3, 4 wrong
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
1. Blood plasma is the fluid portion of blood and constitutes about 55- 60% of the blood.
2. Albumin is the smallest protein present in blood plasma. It maintains osmotic pressure of plasma and also maintains osmotic balance of cells and tissue fluids.
3. Blood contains 13 clotting factors which are named in roman numerals from I to XIII. For example, factor I is fibrinogen, factor II is prothrombin and factor XIII is fibrin stabilising factor.
4. Blood plasma without any clotting factor is called serum.
5. Blood contains many inorganic micronutrients called minerals which are essential for normal body functions such as calcium, iron, phosphorus, sodium etc.
Hence, statements 2,3,4 are correct and 1,5 are incorrect.
So, the correct answer is '2, 3, 4 correct, 1 and 5 wrong'.
Multiple choice biology simple nutrients into cells blood and its components components of blood composition of blood

Globulins contained in human blood plasma are primarily involved in

  1. Clotting of blood

  2. Osmotic balance of body fluids

  3. Defence mechanism of body

  4. Oxygen transport in blood.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Globulins, specifically immunoglobulins (antibodies), are essential components of the immune system and are primarily responsible for the body's defense mechanisms.

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

About _________ percent of $O _{2}$ is carried in dissolved state through the plasma. Choose the correct options.

  1. $a = 9.8\ ml, b = 6000\ ml$ to $8000\ ml, c = 12\ to \ 16, d = 3$
  2. $a = 5\ ml, b = 500\ ml, c = 12\ to \ 16, d = -3$
  3. $a = 9.8\ ml, b = 5\ ml$ to $8000\ ml, c = 12\ to \ 16, d = 3$
  4. $a = 5\ ml, b = 6000\ ml$ to $8000\ ml, c = 18 times, d = 7$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Approximately 3% of oxygen is transported in a dissolved state in plasma. The other values provided in option A are consistent with standard physiological parameters for blood volume and hemoglobin concentration.

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

Raising of pH of blood shall result in

  1. Inhibition of carbonic anhydrase

  2. Production of carbon monoxide and causing carbon monoxide poisoning

  3. Non-release of carbon dioxide from carbonic acid and carbonates

  4. Non-dissociation of oxygen from oxyhaemoglobin.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A decrease in pH (increase in $H^+$ ion concentration) various amino acid residues, such as Histidine 146 exist predominantly in their protonated form allowing them to form ion pairs that stabilize deoxyhemoglobin thereby having a lower affinity for oxygen. So with increased acidity, the hemoglobin binds less $O _2$.This is known as the Bohr effect. The binding affinity of hemoglobin to O2 is greatest under a relatively high pH and oxygen does not disassociate with hemoglobin under increased pH conditions.
So the correct answer is 'Non-dissociation of oxygen from oxyhemoglobin.'
Multiple choice

What is the process by which oxygen is taken up by the body and carbon dioxide is released called?

  1. Respiration

  2. Diffusion

  3. Osmosis

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

Respiration is the process by which oxygen is taken up by the body and carbon dioxide is released.

Multiple choice

What is the role of hemoglobin in the transport of oxygen in the body?

  1. To carry oxygen from the lungs to the tissues

  2. To carry carbon dioxide from the tissues to the lungs

  3. To regulate body temperature

  4. To produce energy from food
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the tissues.

Multiple choice

What is the process by which animals take in oxygen and release carbon dioxide?

  1. Photosynthesis

  2. Cellular respiration

  3. Transpiration

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

Cellular respiration is the process by which animals use oxygen to break down glucose and produce energy.

Multiple choice

Which type of biomolecule is responsible for transporting oxygen in the bloodstream?

  1. Carbohydrates

  2. Proteins

  3. Lipids

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

Proteins, specifically hemoglobin, are responsible for transporting oxygen in the bloodstream and facilitating oxygen delivery to tissues.

Multiple choice

What is the process by which oxygen and carbon dioxide are exchanged in the lungs?

  1. Diffusion

  2. Osmosis

  3. Active transport

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

Oxygen and carbon dioxide are exchanged in the lungs through the process of diffusion, where gases move from areas of higher concentration to areas of lower concentration.

Multiple choice

What is the term for the process by which oxygen moves from the alveoli to the bloodstream?

  1. Diffusion

  2. Perfusion

  3. Ventilation

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

Diffusion is the process by which oxygen moves from the alveoli to the bloodstream across the alveolar-capillary membrane.