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

Pneumatophores are helpful in

  1. transpiration

  2. carbohydrate metabolism

  3. protein synthesis

  4. respiration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pneumatophores are specialized roots found in mangroves that grow upwards out of the waterlogged soil to facilitate gas exchange (respiration) in oxygen-deficient environments.

Multiple choice

Oxygen is transported in blood mainly by __________.

  1. blood platelets

  2. thrombocytes

  3. erythrocytes

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

Erythrocytes, or red blood cells, contain hemoglobin, which is the protein responsible for binding and transporting oxygen in the blood.

Multiple choice

One gram haemoglobin can combine with

  1. 1.3 ml oxygen

  2. 3.5 ml oxygen

  3. 3.1 ml oxygen

  4. 31 ml oxygen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

One gram of hemoglobin can bind approximately 1.34 ml of oxygen, often rounded to 1.3 ml in textbook contexts.

Multiple choice

In the tissues, high concentration 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

The Bohr effect states that high CO2 concentrations increase hydrogen ion concentration (lower pH), which decreases hemoglobin's affinity for oxygen, facilitating oxygen release in tissues.

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 living cells require a medium for gas exchange, which is typically a moist surface. Option B is false because some animals use diffusion directly; C is false because many animals use skin or tracheae; D is false because some organisms are anaerobic.

Multiple choice

Oxygen dissociation curve shifts to right in case of presence of

  1. high CO2 concentration

  2. low CO2 concentration

  3. chemical like DPG

  4. both 1 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The oxygen dissociation curve shifts to the right (Bohr effect) when hemoglobin's affinity for oxygen decreases. This occurs in conditions of high CO2 concentration, low pH, high temperature, and increased levels of 2,3-DPG.

Multiple choice

A condition in which body's internal environment remains relatively constant within limits is called

  1. homeostasis

  2. hemostasis

  3. hematoma

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

A condition in whcih body's internal environment remains relatively constant within limits is called homeostasis homeostatic mechanisms protects an animal's internal environment form harmful fluctuations. It enables animals to survive large flucuations in theri external environment by tempering changes in body fluids. 

Multiple choice

Which among the following gases hampers the transport of oxygen in our body by replacing oxygen in oxyhaemoglobin?

  1. Carbon dioxide

  2. Carbon monoxide

  3. Carbon disulphide

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

Carbon monoxide hampers the transport of oxygen in our body. In lungs, oxygen combines with haemoglobin present in blood and is transported to all parts of the body. However, carbon monoxide if inhaled, displaces oxygen and forms carboxyhaemoglobin.

Multiple choice

Why do gases diffuse over the respiratory surface?

  1. Because pO2 is more in alveoli than in blood.

  2. Because pO2 is more in blood than in tissues.

  3. Because pCO2 is less in alveoli than in blood.

  4. Because pCO2 is less in blood than in tissues.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gases diffuse over the respiratory surface because pO2 is more in alveoli than in blood.

Multiple choice

At high altitudes, the RBCs in human blood

  1. increase in number

  2. decrease in number

  3. decrease in size

  4. increase in size
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

At high altitudes, the RBCs in human blood increase in number to meet the increased oxygen demand.