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

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.

Multiple choice

Which of the following substances is/are transported by blood plasma?

  1. Food

  2. Potassium

  3. Alcohol

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

Blood consists of a fluid medium known as plasma, in which red blood cells (RBCs), white blood cells (WBCs) and platelets are suspended. Plasma transports food (nutrients), carbon dioxide and nitrogenous wastes in dissolved form. Potassium (K) - Mineral nutrients are supplied by plasma. K helps in contraction of muscles and in sending nerve impulse. Alcohol - Alcohol is also transported by blood plasma. BAC (Blood Alcohol Concentration) is the concentration of alcohol in a person's blood. Alcohol is quickly absorbed in the blood. High intake of alcohol decreases the level of beta-carotene in plasma. (Beta-carotene is used for formation of vitamin A.)

Multiple choice

One molecule of hemoglobin binds

  1. 2 O2 molecules

  2. 4 O2 molecules

  3. 1 O2 molecules

  4. 3 O2 molecules
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Each hemoglobin molecule contains four heme groups, allowing it to bind up to four molecules of oxygen (O2).

Multiple choice

Why is aerobic respiration more advantageous than anaerobic respiration?

  1. Because it requires oxygen

  2. Because it produces more energy

  3. Because it causes complete breakdown of respiratory substrate

  4. Because it produces water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can just split glucose into two molecules of pyruvate. This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules.

Multiple choice

What does RQ indicate?

  1. Effect of temperature

  2. Nature of respiratory substrate

  3. Amount of water released

  4. Type of alcohol formed
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

RQ indicates nature of respiratory substrate.It is the ratio of the volume of carbon dioxide evolved to that of oxygen consumed by an organism, tissue, or cell in a given time.

Multiple choice

Which of the following processes is complementary to respiration?

  1. Circulation

  2. Photosynthesis

  3. Osmoregulation

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

Photosynthesis is complementary to respiration.as the products of one reaction are the reactants of another.So, cellular respiration consumes sugars and oxygen and creats carbon dioxide, water, and releases energy. Photosynthesis combines energy, carbon dioxide, and water to form sugar and oxygen.

Multiple choice

Cabon monoxide inhibits mitochondrial electron transport by

  1. inhibiting the electron transfer of complex I

  2. blocking electron transport at the level of the cytochrome b-cytochrome c, complex

  3. binding to the oxygen-binding site of cytochrome oxidase

  4. binding to haemoglobin in the erythrocytes and therefore, blocking the transport of oxygen to tissues
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbon monoxide inhibits mitochondrial electron transport by blocking electron transport at the level of the cytochrome b-cytochrome c, complex.