Biology

Respiration and Gas Exchange

989 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

During inhalation, the diaphragm becomes

  1. flattened

  2. oblique

  3. dome shaped

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

During inhalation, the diaphragm becomes flattened to increase the surface area of the lungs so that more air can enter inside them. So, option 1 is correct.

Multiple choice

The air passing through the nostrils in humans is filtered by

  1. the mucus and innermost surface of nostrils

  2. the mucus and fine hairs in the nostrils

  3. fine hairs, mucus and innermost surface of nostrils

  4. fine hairs and innermost surface of nostrils
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The air passing through the nostrils is filtered by the fine hairs and mucus present in the nostrils. So, option 2 is correct.

Multiple choice

Which of the following statements are false? P. Breathing and respiration are synonymous. Q. Breathing is a biochemical process. R. No energy is released during breathing. S. Breathing is an extracellular process. Select the correct answer using codes given below:

  1. P and Q

  2. P and R

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Breathing and respiration are not synonymous. Breathing is first step of respiration which refers to the intake of fresh air inside and removal of foul air outside the respiratory organs. Respiration is a biochemical process by which organic compounds in food are oxidized to carbon dioxide, water and energy in a stepwise process. Breathing is physical process.

Multiple choice

Which of the following matches of disorders of respiratory systems and their causes is not correct?

  1. Hypoxia : Oxygen shortage at tissue level

  2. Asphyxia : Increase in CO2 concentration in tissues

  3. Emphysema : viral infection

  4. Pneumonia : Bacterial infection

  5. Asthma : Hypersensitivity of the bronchioles to the foreign substances present in air that passes them
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Emphysema is due to the inflation or abnormal distension of the bronchioles or alveolar sacs resulting in loss of their elasticity.

Multiple choice

Which of the following is the unit of respiration rate?

  1. Number of breaths per day

  2. Number of breaths per second

  3. Number of breaths per hour

  4. Number of breaths per minute
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Respiration rate is number of breaths per minute. Normal breathing rate for humans is 12-20 breaths per minute.

Multiple choice

Where does the exchange of gases take place during breathing?

  1. Nostrils

  2. Trachea

  3. Alveoli

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

The exchange of gases takes place in the alveoli. The walls of the alveoli are surrounded by a network of blood capillaries. Thin walls of alveoli and capillaries allow for O2 to enter the capillaries and CO2 to enter the alveoli for exhalation.