NCERT Breathing Exchange Gases model,mock,grand exam,mcq NEET

Breathing and Exchange of Gases Mock Test-10

Question No:1

Assertion: Respiratory rhythm is maintained by the respiratory centre in medulla region of brain.
Reason: A chemo sensitive area in the medulla can alter respiratory mechanism.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:2

Assertion: The maximum amount of CO, is converted in bicarbonate ion in RBCs
Reason: RBCs contain a very high concentration of the enzyme, carbonic anhydrase.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:3

Assertion: Blood of insects is colourless
Reason: The blood of insect does not play any role in transport of oxygen.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:4

Assertion: In mollusca, circulatory system is of closed type.
Reason: The blood of mollusca contains haemoglobin

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:5

Assertion: The amount of COthat can diffuse through the diffusion membrane per unit difference in partial pressure is much higher compared to that of O2
Reason: The solubility of CO2 is 20 — 25 tunes higher than that of O2.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:6

Listed below are four respiratory capacities (1-4) and four jumbled respiratory volumes of a normal human adult
Respiratory capacities Respiratory volumes
(a) Residual volume— 2500 mL
(b) Vital capacity —3500 mL
(c) Inspiratory reserve volume— 1200mL
(d) Inspiratory capacity— 4500 mL
Which one of the following is the correct matching of two capacities and volumes?

[A] (b)2500mL (c) 4500 mL
[B] (c) 1200 mL (d) 2500 mL
[C] (d)3500mL (a) 1200 mL
[D] (a)4500mL (b) 3500 mL



Question No:7

What is true about RBCs in humans?

[A] They carry about 20-25 per cent of CO2
[B] They transport 99.5 per cent of O2
[C] They transport about 80 per cent oxygen only and the rest 20 per cent of it is transported in dissolved state in blood plasma
[D] They do not carry O2 at all



Question No:8

Two friends are eating together on a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of:

[A] Diaphragm
[B] Neck
[C] Tongue
[D] Epiglottis



Question No:9

Which one of the following is a possibility for most of us in regard the breathing by making a conscious effort?

[A] One can breathe out air totally without oxygen
[B] One can breathe out air through Eustachian tube by closing both nose and mouth
[C] One can consciously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all
[D] The lungs can be made fully empty by forcefully breathing out all air from them



Question No:10

Bulk of carbon dioxide CO2 released from body tissues into the blood is present as

[A] Bicarbonate in blood plasma and RBCs
[B] Free CO2 in blood plasma
[C] 70% carbamino-haemoglobin and 30% as bicarbonate
[D] Carbamino-haemoglobin in RBCs



Question No:11

A large proportion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O2

[A] Raises the pco2co of blood to 75 mm of Hg
[B] Is enough to keep oxyhaemoglobin
[C] Helps in relasing more O2 the epithelial tissue’s
[D] Acts as a reserve during muscular exercise



Question No:12

Which one of the following is the correct statement for respiration in humans?

[A] Cigarette smoking may lead to inflammation of bronchi
[B] Neural signals form pneumotoxic centre in pons region of brain can increase the duration of inspiration
[C] Workers in grinding and stone-breaking industries may suffer, from lung fibrosis
[D] About 90% of carbon dioxide CO2 is carried by haemoglobin as carbamino haemoglobin



Question No:13

Approximately seventy percent of carbon —dioxide absorbed by the blood will be transported to the lungs:

[A] As bicarbonate ions
[B] In the form of dissolved gas molecules
[C] By binding to R.B.C.
[D] As carbamino – haemoglobin



Question No:14

When you hold your breath, which of the following gas changes in blood would first lead to the urge in breathe?

[A] Falling O2 concentration
[B] Rising CO2 concentration
[C] Falling CO2 concentration
[D] Rising CO2 and falling O2 concentration



Question No:15

Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls

[A] Emphysema
[B] Pneumonia
[C] Asthma
[D] Pleurisy