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

Contractions of the external intercostal muscles bring about

  1. decrease in the volume of thoracic cavity

  2. increase in the volume of thoracic cavity

  3. flattening of the diaphragm

  4. no change in the <font size="2">v</font>olume of thoracic cavity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Contractions of the external intercostal muscles bring about increase in the volume of thoracic cavity.

Multiple choice

Why do mammalian lungs have numerous alveoli?

  1. For increasing volume of inspired air

  2. For keeping the lungs in proper shape and position

  3. For higher number of muscles to provide greater elasticity

  4. For increasing the surface area for gaseous diffusio<font size="2">n</font>

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mammalian lungs have numerous alveoli for increasing the surface area for gaseous diffusion.

Multiple choice

Respiration in frog is performed with the help of

  1. buccal cavity

  2. skin

  3. lungs

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

The frog has three respiratory surfaces on its body that it uses to exchange gas with the surroundings: the skin, in the lungs and on the lining of the mouth.

Multiple choice

What happens to diaphragm at the time of inspiration?

  1. It expands

  2. It contracts

  3. It relaxes

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

During inspiration (breathing in), the diaphragm contracts, drawning downward, creating a vacuum in the thoracic cavity. This vacuum inflates the lungs by drawing air into the body through the trachea, or windpipe.

Multiple choice

Exchange of gases in lung alveoli occurs through

  1. active transport

  2. osmosis

  3. simple diffusion

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

Exchange of gases in lung alveoli occurs through simple diffusion,O2 diffusing from the alveoli into the blood & CO2 from the blood into the alveoli.

Multiple choice

The conducting airways terminate in _________________.

  1. trachea

  2. bronchi and bronchioles

  3. gas-exchange sacs

  4. the lymphatic system
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Inhaled substances that are not deposited in other parts of the respiratory tract get deposited in gas-exchange sacs. The conducting airways terminate in gas-exchange sacs, which are made up of respiratory bronchioles and alveolar ducts.

Multiple choice

Both the skin and the lungs act as respiratory organs in ______________.

  1. amphibians

  2. fish

  3. insects

  4. molluscs

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both the lungs and the skin serve as respiratory organs in amphibians. The skin of these animals is highly vascularized and moist, with moisture maintained via secretion of mucous from specialized cells. While the lungs are of primary importance to breathing control, the skin's unique properties aid rapid gas exchange when amphibians are submerged in oxygen-rich water.

Multiple choice

The nasal chamber opens into ________.

  1. bronchioles

  2. alveoli

  3. nasopharynx

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

The nasal chamber opens into nasopharynx, which is a portion of pharynx, the common passage for food and air. Nasopharynx opens through glottis of the larynx region into the trachea. Larynx is a cartilaginous box which helps in sound production and, hence, called the sound box.

Multiple choice

Wind pipe is commonly known as

  1. trachea

  2. lungs

  3. external nostrils

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

The trachea, or windpipe, divides into two principal bronchi (plural for bronchus) as it enters the lungs. The principal bronchi are further divided into smaller bronchi. Further divisions of the bronchi eventually lead to tiny tubes, called bronchioles, which lead to tiny air sacs known as alveoli.

Multiple choice

Reversible Obstructive Airway Disease (ROAD) is commonly known as

  1. common cold

  2. asthma

  3. ambroxol

  4. bronchitis

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Asthma is a condition in which the airways of the lungs become either narrowed or completely blocked, obstructing normal breathing. This obstruction of the lungs, however, is reversible, either spontaneously or with medication. That is why asthma is technically called Reversible Obstructive Airway Disease (ROAD).

Multiple choice

The dome-shaped muscle that helps in the breathing process is known as

  1. nostril

  2. diaphragm

  3. alveolus

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

Breathing begins with a dome-shaped muscle located at the bottom of the lungs which is known as diaphragm. When we breathe in, the diaphragm contracts and flattens out and pulls downward. Due to this movement the space in the lungs increases and pulls air into the lungs. When we breathe out, the diaphragm expands and reduces the amount of space for the lungs and forces air out.