Breathing And Exchange of Gases

Question 1

What is the primary function of oxygen (O2) in organisms?

Answer 1

To indirectly break down simple molecules like glucose, amino acids, and fatty acids to derive energy

Oxygen is essential for cellular respiration, which produces energy for various activities.

Question 2

What harmful substance is released during catabolic reactions?

Answer 2

Carbon dioxide (CO2)

CO2 is a byproduct of metabolism and must be expelled from the body.

Question 3

What is the process of exchanging oxygen from the atmosphere with carbon dioxide produced by cells called?

Answer 3

Breathing, commonly known as respiration

This process is crucial for maintaining the balance of gases in the body.

Question 4

How do lower invertebrates like sponges and flatworms exchange gases?

Answer 4

By simple diffusion over their entire body surface

This method relies on the direct exchange of gases with the surrounding environment.

Question 5

What structures do earthworms use for gas exchange?

Answer 5

Moist cuticle

The moisture in their skin facilitates the diffusion of gases.

Question 6

What is the function of tracheal tubes in insects?

Answer 6

To transport atmospheric air within the body

This system allows for efficient oxygen delivery directly to tissues.

Question 7

What are gills used for in aquatic arthropods and mollusks?

Answer 7

Branchial respiration (gas exchange)

Gills are specialized structures that extract oxygen from water.

Question 8

What type of respiration do terrestrial forms of animals primarily use?

Answer 8

Pulmonary respiration (lungs)

Lungs are adapted for gas exchange in air.

Question 9

Which respiratory structures do fishes use?

Answer 9

Gills

Gills allow fishes to extract oxygen from water.

Question 10

What unique method of respiration can amphibians like frogs use?

Answer 10

Cutaneous respiration (through their moist skin)

This allows amphibians to absorb oxygen directly from their environment.

Question 11

What opens into the nasal chamber?

Answer 11

External nostrils

Question 12

What is the common passage for food and air?

Answer 12

Pharynx

Question 13

What is the function of the larynx?

Answer 13

Sound production

Question 14

What prevents the entry of food into the larynx during swallowing?

Answer 14

Epiglottis

Question 15

What does the trachea divide into?

Answer 15

Right and left primary bronchi

Question 16

Where does the trachea divide?

Answer 16

At the level of the 5th thoracic vertebra

Question 17

What supports the trachea and bronchi?

Answer 17

Incomplete cartilaginous rings

Question 18

What are the very thin, irregular-walled structures called that arise from terminal bronchioles?

Answer 18

Alveoli

Question 19

What comprises the lungs?

Answer 19

Branching network of bronchi, bronchioles, and alveoli

Question 20

How many lungs do we have?

Answer 20

Two

Question 21

What covers the lungs?

Answer 21

Double layered pleura

Question 22

What is located between the layers of the pleura?

Answer 22

Pleural fluid

Question 23

What does pleural fluid reduce?

Answer 23

Friction on the lung-surface

Question 24

The outer pleural membrane is in close contact with the _______.

Answer 24

Thoracic cavity

Question 25

What is the inner pleural membrane in contact with?

Answer 25

The lung surface

Question 26

What constitutes the conducting part of the respiratory system?

Answer 26

The part starting with the external nostrils up to the terminal bronchioles

Question 27

What is the function of the conducting part of the respiratory system?

Answer 27

Transports atmospheric air to the alveoli, clears it from foreign particles, humidifies, and brings the air to body temperature

Question 28

What is the exchange part of the respiratory system made up of?

Answer 28

The alveoli and their ducts

Question 29

What occurs at the exchange part of the respiratory system?

Answer 29

Diffusion of O2 and CO2 between blood and atmospheric air

Question 30

Where are the lungs situated?

Answer 30

In the thoracic chamber

Question 31

What forms the thoracic chamber?

Answer 31

Dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and lower side by the diaphragm

Question 32

What happens to the lung cavity when there is a change in the volume of the thoracic cavity?

Answer 32

It is reflected in the lung (pulmonary) cavity

Question 33

What is the first step of respiration?

Answer 33

Breathing or pulmonary ventilation

Question 34

What is the second step of respiration?

Answer 34

Diffusion of gases (O2 and CO2) across alveolar membrane

Question 35

What is the third step of respiration?

Answer 35

Transport of gases by the blood

Question 36

What is the fourth step of respiration?

Answer 36

Diffusion of O2 and CO2 between blood and tissues

Question 37

What is the fifth step of respiration?

Answer 37

Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2

Question 38

What are the two stages of breathing?

Answer 38

Inspiration and expiration

Question 39

What creates the pressure gradient for air movement during breathing?

Answer 39

Difference between intra-pulmonary pressure and atmospheric pressure

Question 40

What initiates inspiration?

Answer 40

Contraction of the diaphragm

Question 41

What happens to the thoracic chamber during inspiration?

Answer 41

The volume increases in the antero-posterior axis

Question 42

What muscles assist in the movement of air during breathing?

Answer 42

Diaphragm and external and internal intercostals

Question 43

Fill in the blank: Expiration takes place when the intra-pulmonary pressure is _______ than the atmospheric pressure.

Answer 43

higher

Question 44

True or False: The diaphragm helps in decreasing the volume of the thoracic chamber during inspiration.

Answer 44

False