Decreases surface tension of fluid lining alveoli

Protein produced by type II alveolar cells

Excessive in many premature infants causing difficulty in breathing

Lacking in individuals suffering from acute respiratory distress syndromes

MCQ Questions for Class 11 Medical Biology Breathing And Exchange Of Gases Quiz 9

How many cartilages form larynx?

0%
$6$
0%
$15$
0%
$9$
0%
$12$

Oxygen binding to haemoglobin is

0%
Directly proportional to $CO_2$ concentration
0%
Directly proportional to CO concentration
0%
Inversely proportional to $CO_2$ concentration
0%
Independent of CO concentration

Explanation

With the increase in the level of CO $_2$ , the pH of blood becomes acidic and simultaneously haemoglobin's affinity for oxygen decreases.
This means that haemoglobin holds on to oxygen-less tightly, thus releasing it more readily.
So, oxygen binding to haemoglobin is inversly proportional to CO $_2$ concentration.

Volume of air which remains in conduction airways and is not available for gas exchange is?

0%
Vital capacity
0%
Anatomic dead space
0%
Functional residual capacity
0%
Forced expiratory volume

Which is not function of 'conducting part' of respiratory system?

0%
Clears the air from foreign particles
0%
Humidifies the air
0%
Brings the air to body temperature
0%
It is site for diffusion of oxygen and carbon dioxide
0%
Transports air to alveoli

Explanation

The conducting part transports the atmospheric air to the alveoli, clears it from foreign particles, humidifies and also brings the air to body temperature. Exchange part is the site of actual diffusion of

$O_2$ and

$CO_2$ between blood and atmospheric air that occurs in the alveoli.

Hence the correct answer is (D)

Amount of Oxygen carried by

$100$ ml arterial blood while passing through tissues is?

0%
$0.4 - 0.6$ $ml
0%
$4 - 6$ ml
0%
$14 - 15$ ml
0%
$19 - 20$ ml

Read the following statements regarding the mechanism of respiration and choose the correct option.

$1$ . Inspiration occurs only when there is negative pressure in the lungs with respect to the atmosphere.

$2$ . Expiration takes place only when intrapulmonary pressure is lower than atmospheric pressure.

$3$ . Pressure gradients are generated with the help of the diaphragm and intercostal muscles.

$4$ . Inspiration is initiated by the relaxation of the diaphragm.

$5$ . Contraction of the diaphragm reduces pulmonary volume and increases intrapulmonary pressure causing expiration.

0%
$1, 2$ and $5$ correct
0%
$2$ only correct
0%
$2, 5$ correct
0%
$1, 3$ correct
0%
$1, 4$ correct

Find the correctly matched pair.

0%
$CO_2$ transported by RBCs about $3\%$
0%
$CO_2$ carried in dissolved state through plasma- $20-25\%$
0%
$O_2$ transported by RBCs in blood - $97\%$
0%
$CO_2$ carried as bicarbonate - $7\%$
0%
$O_2$ carried in dissolved state through plasma - $7\%$

Increased body temperature makes oxygenhaemoglobin dissociation curve to.

0%
Shift right
0%
Shift left
0%
Become parabolic
0%
Become hyperbolic

Surfactant is?

0%
Protein produced by type II alveolar cells
0%
Excessive in many premature infants causing difficulty in breathing
0%
Decreases surface tension of fluid lining alveoli
0%
Lacking in individuals suffering from acute respiratory distress syndromes

Alveoli occur in ______.

0%
Lungs
0%
Liver
0%
Kidney
0%
Brain

Bronchial respiration occurs with the help of.

0%
Book lungs
0%
Gills
0%
Trachea
0%
Pulmonary sac

Which has more affinity for haemoglobin?

0%
Carbon monoxide
0%
Carbon dioxide
0%
Oxygen
0%
Both B and C

Match and find the correct option.

	I		II
(a)	$pCO_2$ of alveoli of lungs	(i)	$40$ mm Hg
(b)	$pO_2$ of atmospheric air	(ii)	$95$ mm Hg
(c)	$pO_2$ of deoxygenated blood	(iii)	$104$ mm Hg
(d)	$pO_2$ of oxygenated blood	(iv)	$159$ mm Hg

0%
a-iii, b-ii, c-i, d-iv
0%
a-ii, b-iv, c-iii, d-i
0%
a-ii, b-iv, c-i, d-iii
0%
a-iii, b-iv, c-i, d-ii

Which of the following is the most appropriate in normal circumstances?

0%
During inspiration the intrapulmonary pressure is less than the atmospheric pressure
0%
During expiration the intrapulmonary pressure is less than the atmospheric pressure
0%
During inspiration the intrapulmonary pressure is more than the atmospheric pressure
0%
During expiration the intrapulmonary pressure is equal to atmospheric pressure

Number of alveoli present in human lungs is?

0%
$7-10$ million
0%
$70-100$ million
0%
$300-400$ million
0%
$800-1000$ million

A molecule of haemoglobin can carry atoms of oxygen.

0%
$2$
0%
$4$
0%
$6$
0%
$8$

Identify correct statement regarding transport of respiratory gases through blood

0%
Only oxygen is transported
0%
Only $CO_2$ is transported
0%
Haemoglobin is necessary for transport of $O_2$ and carbonic anhydrase for $CO_2$
0%
Haemoglobin is necessary for transport of $CO_2$ and carbonic anhydrase for $O_2$ .

Volume of air inspired and expired with each normal breath is known as

0%
Residual Volume (RV)
0%
Total Lung Capacity (TLC)
0%
Vital Capacity (VC)
0%
Tidal Volume (TV)

Pulmonary trunk and aorta are attached by

0%
Chordae tendinae
0%
Ligamentum arteriosus
0%
Coronary sulcus
0%
Pericardium.

Which of the following increases area of thoracic cavity during inhalation?

0%
Outward and upward movement of rib-cage
0%
Outward and downward movement of rib-cage
0%
Inward and downward movement of rib-cage
0%
Inward and upward movement of rib-cage

What does the part labeleld 'a' in the given diagram indicate

0%
White pulp
0%
Sinus
0%
Medulla
0%
Cortex

Which structure of the lungs is directly involved in O

$_2$ /CO

$_2$ exchange between air and blood capillary?

0%
Bronchi
0%
Trachea
0%
Alveoli
0%
Secondary bronchi

People who have migrated from the planes to an area adjoining Rohtang Pass about six month back.

0%
Have more RBCs and their haemoglobin has a lower binding affinity to $O_{2}$
0%
Are not physically fit to play games like football
0%
Suffer from altitude sickness with symptoms like nausea, fatigue, etc
0%
Have the usual RBC count but their haemoglobin has very high binding affinity to $O_{2}$

Explanation

People who have migrated from the planes to an area adjoining Rohtang Pass about six months back have more RBCs and their haemoglobin has a lower binding affinity to O

$_2$ . As a person goes uphill pO

$_2$ decreases and altitude increases. Due to lower pO

$_2$ , the affinity of haemoglobin towards O

$_2$ decreases. On hills, the O

$_2$ level decreases. To compensate this decrease, more RBCs are produced.

Thus, the correct answer is option A.

The entry of food into the larynx is prevented by

0%
Mitral valve
0%
Diaphragm
0%
Frenulum
0%
Epiglottis

Emphysema is a

0%
Cardiovascular disease
0%
Pulmonary disease
0%
Neural disease
0%
Renal disease

After forceful inspiration, the amount of air that can be breathed out by maximum forced expiration is equal to.

0%
Inspiratory Reserve Volume(IRV) $+$ Expiratory Reserve Volume (ERV) $+$ Tidal Volume (TV) $+$ Residual Volume(RV)
0%
IRV $+$ RV $+$ ERV
0%
IRV $+$ TV $+$ ERV
0%
TV $+$ RV $+$ ERV

Mark the incorrect statement in context to

$O_2$ binding to Hb.

0%
Higher pH
0%
Lower temperature
0%
Lower $pCO_2$
0%
Higher $PO_2$

Diastasis amounts to which of the following?

0%
2.91% of end diastolic volume
0%
2.91% of end systolic volume
0%
5% of cardiac output
0%
2.91% of stroke volume.

Arrange the following terms regarding process of respiration in chronological order of its decreasing volume of air
I. Expiratory reserve volume
II. Vital capacity
III. Tidal volume
IV. Residual volume

0%
$II \rightarrow IV \rightarrow I \rightarrow III$
0%
$II \rightarrow IV \rightarrow III \rightarrow I$
0%
$I \rightarrow IV \rightarrow III\rightarrow II$
0%
$IV \rightarrow I \rightarrow III\rightarrow I$

Name the chronic respiratory disorder caused mainly by cigarette smoking:-

0%
Emphysema
0%
Asthma
0%
Respiratory acidosis
0%
Respiratory alkalosis.

Which among the following serves the function of lung surfactant?

0%
Phospholipoprotein
0%
Peptidoglycan
0%
Lecithin
0%
Chitin

Membrane separating air in pulmonary alveoli from blood capillaries.

0%
Alveolar epithelium
0%
Cardiac epithelium
0%
Endothelium of blood capillaries
0%
Both $'1'$ and $'3'$

Name the chronic respiratory disorder caused mainly by cigarette smoking.

0%
Asthma
0%
Respiratory acidosis
0%
Respiratory alkalosis
0%
Emphysema

How the transport of

$O_2$ and

$CO_2$ by blood happens?

0%
With the help of WBCs and blood serum
0%
With the help of platelets and corpuscles
0%
With the help of RBCs and blood plasma
0%
With the help of RBCs and WBCs

A person breathes in some volume of air by forced inspiration after having a forced expiration. This quantity of air taken in is _______________.

0%
Total lung capacity
0%
Tidal volume
0%
Vital capacity
0%
Inspiratory capacity

During inspiration, the pressure of air is maximum in ___________.

0%
Trachea
0%
Bronchus
0%
Alveoli
0%
Environment

The given graph shows various pulmonary air volumes and capacities. What is depicted by X and Y in the graph?

0%
Functional residual capacity and vital capacity
0%
Total lung capacity and inspiratory capacity
0%
Vital capacity and total lung capacity
0%
Inspiratory capacity and functional residual capacity

Compared to the atmospheric air, the alveolar air has

0%
More $pO_2$ and less $pCO_2$
0%
Less $pO_2$ and more $pCO_2$
0%
More $pO_2$ and more $pCO_2$
0%
Less $pO_2$ and less $pCO_2$

Explanation

The partial pressure of oxygen (pO

$_2$ ) in the atmospheric air is higher than the partial pressure of oxygen (pO

$_2$ ) in alveolar air. In atmospheric air, pO

$_2$ is about 159 mm of Hg. In alveolar air, it is about 104 mm of Hg. The partial pressure of carbon dioxide (pCO

$_2$ ) in atmospheric air is lesser than the partial pressure of carbon dioxide (pCO

$_2$ ) in alveolar air. In atmospheric air, pCO

$_2$ is about 0.3 mm of Hg. In alveolar air, it is about 40 mm of Hg. The less pO

$_2$ in the alveolar air helps in more absorption of O

$_2$ . The high pCO

$_2$ in the atmospheric air helps in release of CO

$_2$ into the air.

Thus, the correct answer is option B.

Given below are few respiratory disorders. Identify occupational respiratory disorders among these.
(i) Coryza
(ii) SARS
(iii) Silicosis
(iv) Asbestosis
(v) Emphysema

0%
(i) and (ii)
0%
(i) and (v)
0%
(iii) and (iv)
0%
(i), (ii) and (v)

Which of these epithelia is chiefly involved in function like diffusion and thereby is found in the wall of blood vessels and air sacs of the lungs?

Oxygen dissociation curve of haemoglobin is

0%
Sigmoid.
0%
Hyperbolic.
0%
Linear.
0%
Hypobolic.

The sigmoid shape of the dissociation curve is because

0%
Binding of oxygen to haemoglobin. As the first oxygen molecule binds to haemoglobin, it increases the affinity for the second molecule of oxygen to bind. Subsequently, haemoglobin attracts more oxygen.
0%
The curve shows the equilibrium of oxyhaemoglobin and haemoglobin
0%
In the lungs,the partial pressure of oxygen is high
0%
Tissues have a low oxygen concentration

Gaseous exchange of oxygen and carbon dioxide between alveolar air and capillaries takes place by

0%
Active transport.
0%
Diffusion.
0%
Carrier-mediated transport.
0%
Imbibition.

Explanation

Diffusion is a phenomenon in which molecules move from an area of high concentration to an area of low concentration. An example of this process is gaseous exchange of oxygen and carbon dioxide between alveolar air and capillaries. The blood in the capillaries surrounding the alveoli has a lower concentration of oxygen than the oxygen in the inhaled air. Hence, O

$_2$ diffused from the alveoli to the capillaries. The blood in the surrounding capillaries has a higher concentration of carbon dioxide than the inspired air. Hence, CO

$_2$ diffuses from the capillaries into the alveoli where it is then exhaled.

Thus, the correct answer is option B.

The maximum number of oxygen molecules that can bind to one molecule of hemoglobin is

0%
$8$
0%
$6$
0%
$4$
0%
$2$

Direction: Refer the given graph and select the correct options
Which of these is correct regarding D, E and F areas in the graph?

0%
D shows venous blood during exercise
0%
E shows normal venous blood
0%
F shows normal arterial blood
0%
All of these

Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because ____________________.

0%
There is a negative pressure in the lungs.
0%
There is a negative intrapleural pressure pulling at the lung walls.
0%
There is a positive intrapleural pressure.
0%
Pressure in the lungs is higher than the atmospheric pressure.

The ultimate end parts of the respiratory system in humans are known as

0%
alveoli
0%
bronchioles
0%
tracheoles
0%
bronchi

Which structure gives us ability to speech?

0%
Epiglottis
0%
Vocal cord
0%
Larynx
0%
Trachea

Which of the following represent correct blood flow pathway in pulmonary circulation?

0%
Right Ventricle $\underrightarrow { Aorta }$ Lung $\underrightarrow { Pulmonary\ Vein }$ Left Atrium
0%
$\underrightarrow { Pulmonary\ Vein }$ Left Atrium $\longrightarrow$ Lung $\underrightarrow { Pulmonary\ Vein }$ Left Atrium
0%
Right Ventricle $\underrightarrow { Pulmonary\ Vein }$ Lung $\underrightarrow { Pulmonary\ artery }$ Left Atrium
0%
$\underrightarrow { Pulmonary\ Vein }$ Right Atrium Lung $\underrightarrow { Pulmonary\ Vein }$ Right Atrium

Explanation

The human heart is four-chambered divided into two atrium and two ventricles. Blood follows in the direction as shown in the above figure.

So, the correct option is 'Right Ventricle

$\underrightarrow { Aorta }$ Lung

$\underrightarrow { Pulmonary\ Vein }$ Left Atrium'.

1162150_853096_ans_910c0e9aa3544d858a8a96d6ff95ffae.gif

Choose the correct answer from the alternatives given.
Site of gaseous exchange in lungs is:

0%
pulmonary chamber
0%
trachea
0%
bronchioles
0%
alveoli

CBSE Questions for Class 11 Medical Biology Breathing And Exchange Of Gases Quiz 9 - MCQExams.com

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Practice Class 11 Medical Biology Quiz Questions and Answers

CBSE Questions for Class 11 Medical Biology Breathing And Exchange Of Gases Quiz 9 - MCQExams.com

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Practice Class 11 Medical Biology Quiz Questions and Answers

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