NCERT Breathing Exchange Gases model,sample,mock exam,mcqs NEET

Breathing and Exchange of Gases Mock Test-7

Question No:1

CO2 dissociates from Carbaminohaemoglobin when

[A] low PO2, low PCO2
[B] high PO2, high PCO2
[C] low PO2, high PCO2
[D] high PO2, low PCO2



Question No:2

Dissociation of oxyhaemoglobin can be promoted by

[A] Low pCO2
[B] High pCO2
[C] Low body temperature
[D] High blood pH



Question No:3

Enzyme essential for transport of CO2 as bicarbonate in blood is:

[A] Carboxypeptidase
[B] Succinic dehydrogenase
[C] Carbonic anhydrase
[D] Thrombokinase



Question No:4

What is correct about human respiration?

[A] About 90% of CO2 is carried by haemoglobin as Carbaminohaemoglobin
[B] Neural signals from pneumotaxic centre of pens can increase duration of inspiration
[C] Workers in grinding and stone breaking industries may suffer from lung fibrosis
[D] Cigarette smoking leads to inflammation of bronchi



Question No:5

Choose the right sequential phenomena during passage of CO2 from blood to tissues:
(P) Absorption of CO2 by blood.
(Q) Reaction of CO2 with water forming H2CO3 inside RBCs and then and HCO3 and H+ ions.
(R) Reaction of CO2 with water forming H2CO3 inside plasma followed by conversion into H+ and HCO3 ions.
(S) Combination of H+ with haeme part of HbO2 to release O2
(T) Combination of HCO3 with haeme part of HbO2 to form reduced haemoglobin and release of O2.

[A] P,R,S
[B] P,Q,T
[C] P, Q, S
[D] P,R,T



Question No:6

The transport of CO2 by the blood in primarily dependent on the

[A] solubility of CO2 in blood
[B] presence of carbonic anhydrase in RBCs
[C] ability of hemoglobin to bind and transport CO2
[D] ability of other blood proteins



Question No:7

Pick the correct statement:

[A] Contraction of internal intercostals muscles lifts up the ribs and sternum
[B] RBCs transport oxygen only
[C] Thoracic cavity is anatomically an air tight chamber
[D] Healthy man can inspire approximately 500 mL of air per minute



Question No:8

Respiratory rhythm centre is present in which part of brain?

[A] Pons
[B] Medulla oblongata
[C] Cerebrum
[D] Cerebellum



Question No:9

Pneumotaxic centre is present hi

[A] pons
[B] medulla oblongata
[C] cerebrum
[D] cerebellum



Question No:10

Human beings have a significant ability to maintain and moderate the respiratory rhythm to suit the demands of the body tissues. This is done by

[A] endocrine system
[B] neural system
[C] excretory system
[D] all



Question No:11

All of the following factors play role in the regulation of respiratory rhythm except

[A] CO2
[B] H+conc
[C] O2
[D] None of the above



Question No:12

Select the incorrect statement from the following:

[A] Neural signal from Pneumotaxic centre can reduce the duration of inspiration
[B] The role of oxygen in the regulation of respiratory rhythm is quite significant
[C] RBCs contain a very high concentration of the enzyme, carbonic anhydrase and minute quantities of the same is present in the plasma too
[D] CO2 is carried by haemoglobin as carbamino-haemoglobin (about 20-25 per cent)



Question No:13

Receptors associated with aortic and carotid artery can recognize changes in ____ and ___ cone, and send necessary signal to ___ for remedial action,

[A] O2, CO2 pneumotaxic
[B] CO2, H+, rhythm centre
[C] CO2,H+, apneustic centre
[D] O2, H+, pneumotaxic



Question No:14

Carbonic anhydrase is found in high concentration in

[A] leucocytes
[B] blood plasma
[C] erythrocytes
[D] lymphocytes



Question No:15

Controlling centre of normal breathing in mammals lies in

[A] Cerebrum
[B] Cerebellum
[C] Midbrain
[D] Medulla oblongata