Tag: zoology

Questions Related to zoology

Percentage of $O _2$ present in inhaled air in man is about

  1. 21%

  2. 78%

  3. 1%

  4. 43%


Correct Option: A
Explanation:

Inhaled air contains more oxygen used to create energy and less CO$ _2$. It contains 21% O$ _2$, 0.04% CO$ _2$ and 79% Nitrogen. Thus, option A is correct. 

When diaphragm of man is completely dome shaped it shows

  1. End of expiration and beginning of inspiration

  2. Beginning of expiration and end of inspiration

  3. Increased rate of breathing

  4. Decreased rate of breathing


Correct Option: B
Explanation:

The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continuously, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its dome like shape, and air is forced out of the lungs. Diaphragm contracts, moves down and flattens during inhalation and diaphragm relaxes and curves upwards during exhalation. So, when diaphragm of man is completely dome shaped, it shows that beginning of expiration and end of inspiration. Thus, option B is correct. 

Inspiration takes place during

  1. Inhalation

  2. Exhalation

  3. Both A and B

  4. None of the above


Correct Option: A
Explanation:

Inhalation (also known as inspiration) is the flow of air into an organism. It is a vital process for all human life. In humans it is the movement of air from the external environment, through the airways, and into the alveoli. Inhalation begins with the contraction of the muscles attached to the rib cage. This causes an expansion in the chest cavity. Then takes place the onset of contraction of the diaphragm, which results in expansion of the intrapleural space and an increase in negative pressure according to Boyle's Law. This negative pressure generates airflow because of the pressure difference between the atmosphere and alveolus. Air enters, inflating the lung through either the nose or the mouth into the pharynx (throat) and trachea before entering the alveoli. 

Therefore, the correct answer is option A.

In external respiration,

  1. Food is broken down and oxygen is absorbed.

  2. Food is broken down and carbon dioxide is produced.

  3. Oxygen is ejected and carbon dioxide is adsorbed.

  4. None of the above.


Correct Option: D
Explanation:

External respiration also known as breathing refers to a process of inhaling oxygen from the air into the lungs and expelling carbon dioxide from the lungs to the air. Exchange of gases both in and out of the blood occurs simultaneously. External respiration is a physical process during which oxygen is taken up by capillaries of lung alveoli and carbon dioxide is released from blood. Internal respiration or tissue respiration/cellular respiration refers to a metabolic process in which oxygen is released to tissues or living cells and carbon dioxide is absorbed by the blood. Once inside the cell the oxygen is used for producing energy in the form of ATP or adenosine triphosphate. Therefore, the correct answer is option D.

Chloride shift is concerned with the transport of 

  1. $CO _2$ and $O _2$

  2. $N _2$

  3. $CO _2$

  4. $O _2$


Correct Option: C
Explanation:

Chloride shift is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate (HCO$ _{3-}$) and chloride (Cl-) across the membrane of the red blood cells (RBCs).
Therefore, the correct answer is option C.

Percentage of O$ _2$ present in inhaled air in man is about 

  1. 21%

  2. 78%

  3. 1%

  4. 43%


Correct Option: A
Explanation:

Inhaled air contains more oxygen used to create energy and less carbon dioxide. Exhaled air which contains more carbon dioxide produced as a waste product of energy production and less oxygen as it has been used in respiration. Inhaled air contains 21% oxygen, 0.04% CO$ _2$ and 79% N$ _2$. Exhaled air contains 16% oxygen, 4% CO$ _2$ and 79% N$ _2$.

Therefore, the correct answer is option A.

During inspiration, the diaphragm

  1. Becomes dome-shaped

  2. Flattens

  3. Remains unchanged

  4. Rotates sidewise


Correct Option: B
Explanation:

The diaphragm is located below the lungs and is the major muscle of respiration. It is large, dome-shaped muscle that contracts rhythmically and continually. upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its dome-like shape, and is forced out of the lungs.
Therefore, the correct answer is option B.

In man, expired air contains oxygen about 

  1. 4%

  2. 10%

  3. 16%

  4. 20%


Correct Option: C
Explanation:

Inhaled air contains more oxygen used to create energy and less carbon dioxide. Exhaled air which contains more carbon dioxide produced as a waste product of energy production and less oxygen as it has been used in respiration. Inhaled air contains 21% oxygen, 0.04% CO$ _2$ and 79% N$ _2$. Exhaled air contains 16% oxygen, 4% CO$ _2$ and 79% N$ _2$. 

Therefore, the correct answer is option C.

The volume of thoracic cavity increases during

  1. Never

  2. Expiration

  3. Both A and B

  4. Inspiration


Correct Option: D
Explanation:

Increase in volume of thoracic cavity is seen in case of inspiration. Inspiration results in flattened diaphragm. The volume of thoracic cavity decreases during expiration and the diaphragm relaxes and comes to its original dome shape. 

Therefore, the correct answer is option D.

Fill in the blanks:


Component              Inspired air             Expired air
Oxygen                            a                         16.4%
Nitrogen                        79%                        b

  1. a = 5.6%, b = 21.6%

  2. a = 20.96%, b = 79.6%

  3. a = 28.8, b = 98%

  4. a = 1%, b = 2%


Correct Option: B
Explanation:

Component       Inspired air     Expired air

Oxygen                  20.96%            16.4%
Carbon dioxide       0.04%              4%
Nitrogen                   79%               79.6%