Biology

Respiration and Gas Exchange

958 Questions

Access a targeted set of questions on respiration and gas exchange for competitive exams. Topics include lung volumes, the mechanism of breathing, and respiratory anatomy. Understanding these physiological processes is essential for scoring well.

Lung volumes and capacitiesBreathing mechanismsRespiratory anatomyGas exchange processes

Respiration and Gas Exchange Questions

Multiple choice

What is cutaneous respiration?

  1. Respiration in which gaseous exchange takes place through moist body surface

  2. Respiration in which O2 is obtained through thin body wall to blood vessels

  3. Respiration through gills

  4. Respiration through spiracles and a system of trachea and tracheoles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In cutaneous respiration molecular oxygen penetrates through the skin and it is collected by the blood circulation that then distributes the gas to the tissues. Carbon dioxide is also collected from the tissues by the blood and taken to the skin to be eliminated to the environment. So, there is important participation of blood in cutaneous respiration.

Multiple choice

Inhaling _________ in large amounts can cause pulmonary edema.

  1. NO

  2. H2S

  3. SO2

  4. CO2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Inhaling of nitrogen oxides by humans results in pulmonary edema and hemorrhage. Several sensitive plants get adversely affected by NOx even at the concentration of 1 ppm for a day or 0.35 ppm for a few months. The affected plants start shedding their leaves and fruit. Nitrogen oxides cause fading of textile dyes and deterioration of cotton and nylon fabrics.

Multiple choice

The act of pushing air out of lungs is called

  1. respiration

  2. transpiration

  3. perspiration

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

Expiration is the physiological process of actively breathing out or pushing air from the lungs, involving diaphragm relaxation and thoracic cavity volume decrease.

Multiple choice

Where does the exchange of gases take place in humans?

  1. Alveoli

  2. Bronchi

  3. Trachea

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

The gaseous exchange occurs over the area, which is thin and moist, and has a huge surface area and is richly supplied by blood. These are the properties of alveoli. On the contrary, trachea, bronchi and bronchioles are passages of the respiratory system, which lead to the alveoli. But, exchange of gases cannot occur here because they are not thin and are not richly supplied with blood to allow quick diffusion of gases for exchange.

Multiple choice

When the Respiratory Quotient (RQ) is greater than 1, it indicates

  1. only aerobic respiration is taking place

  2. only anaerobic respiration is taking place

  3. both aerobic and anaerobic respirations are taking place

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

The Respiratory Quotient (RQ) is the ratio of CO2 produced to O2 consumed. An RQ greater than 1 occurs when organic acids are oxidized or when anaerobic respiration (which produces CO2 without consuming O2) occurs alongside aerobic respiration.

Multiple choice

Human breathing at a place

  1. increases the dryness of air

  2. decreases the dryness of air

  3. does not alter the dryness

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

Human exhalation contains a high concentration of water vapor from the lungs. Adding this moisture to the surrounding environment increases the humidity, which is the opposite of dryness.

Multiple choice

Aves breathe through

  1. lungs

  2. gills

  3. scales

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

Aves (birds) are vertebrates that breathe through lungs. They have a highly efficient respiratory system involving air sacs.

Multiple choice

Which of the following conditions causes friction during breathing?

  1. Pulmonary edema

  2. Pleurisy

  3. Pleural effusion

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

Pleurisy is caused by inflammation of the linings around the lungs (the pleura). Inflammation of the pleural membrane causes friction during breathing which is quite painful when the swollen membranes rub against each other.

Multiple choice

What is Hering-Breuer reflex?

  1. A reflex for the nervous control of respiration

  2. A reflex for the chemical control of respiration

  3. A reflex for behavioural control of respiration

  4. The mechanism of transport of CO2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hering-Breuer reflex happens during nervous control of respiration. It inhibits inspiration by sending impulses to the inspiratory centre to stop inspiration.