Monday, August 30, 2021

Focus Area 2021 | Questions and Answers | Plus One Zoology | Breathing and Exchange of Gases

BREATHING AND EXCHANGE OF GASES


1.   ………. are the structural and functional units of lungs. (Score 1)


Answer: Alveoli


2.   Lungs are covered by double-layered ………. (Score 1)


Answer: Pleura


3.   Note the relationship between the first pair and fill up the blank. (Score 1)

TV: 500 ml                

RV: ……….


Answer: 1100 – 1200 ml


4.   Expand and distinguish between the following abbreviations: (Score 2)

a.   TV                b.  RV

Answer:

a.   Tidal Volume: Volume of air inspired or expired during normal respiration.

b.   Residual volume: Volume of air remaining in the lungs after a forcible expiration.


5.   Analyze the concept map given below and if have a mistake, reconstruct it. (Score 2)



Answer:



6.     Differentiate inspiration and expiration. (Score 2)

Inspiration

Expiration

……………………

……………………

……………………

……………………


Answer:

Inspiration

Expiration

·   Active intake of air into lungs.

·   Diaphragm and external intercostal muscles contract.

·   Passive expelling of air from the lungs.

·   Diaphragm and external intercostal muscles relax.


7.   a) Identify the graph given below. (Score 3)



b) Find out the PO2 at which 90% saturation of haemoglobin with oxygen occurs.

c) List the factors responsible for the formation and dissociation of oxyhaemoglobin.


Answer:

a) Oxygen-Hb dissociation curve.

b) 60 mm Hg

c) pO2, pCO2, H+ concentration, Temperature.


8.   Asthma and emphysema are two disorders of the human respiratory system. Mention their causes and symptoms. (Score 2)

Answer:

Asthma: Difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles.

Emphysema: Damage of alveolar walls. Major cause is cigarette smoking.


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