NEET and AIPMT NEET Zoology Breathing and Exchange of Gases MCQ Questions Solved


When under certain conditions, the P50 value of haemoglobin rises, the affinity of the pigment of combining with O2 will

(1) Remain same

(2) Rise

(3) Fall

(4) First rise and then fall

Audio Explanation:


The P50 is the oxygen partial pressure at which hemoglobin is 50% saturated. The normal P50 is 26.7 mm Hg.

Shifting the oxyhemoglobin dissociation curve to the right, increases P50 and lowers hemoglobin’s affinity for oxygen. 

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In human beings, oblique fissures are associated with :

(1) Right lung

(2) Left lung

(3) Both lungs

(4) None of the above

Audio Explanation:


Oblique fissure

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Hemoglobin that is bonded to carbon monoxide and therefore cannot transport oxygen, is called

1. carboxyhemoglobin

2. methemoglobin

3. reduced hemoglobin

4. carbaminohemoglobin

Audio Explanation:


Carbaminohemoglobin is actually carbon dioxide attached to hemoglobin. CO binds to the same place where oxygen binds and thus interferes with oxygen transport but the site of attachment of carbon dioxide is different from that of oxygen.

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Which of the following does not shift the oxy-haemoglobin dissociation curve to the right?

1. increased pH

2. increased carbon dioxide

3. increased temperature

4. increased 2,3 -DPG

Audio Explanation:


A decreased pH or increased acidity would shift the curve to the right.

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Which of the following is entirely made of cartilage?

1. Nasal septum

2. Larynx

3. Glottis

4. Trachea

Audio Explanation:


(2) Read page 269, XI NCERT.

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Trachea divides into two a right and left primary bronchi at the level of:

1. Seventh cervical vertebra

2. Third thoracic vertebra

3. Fifth thoracic vertebra

4. Seventh thoracic vertebra

Audio Explanation:


(3) Read page 269, XI NCERT

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Contraction of diaphragm:

1. Increases the volume of the thoracic chamber in the antero-posterior axis

2. Increases the volume of the thoracic chamber in the dorso-ventral axis

3. Decreases the volume of the thoracic chamber in the antero-posterior axis

4. Decreases the volume of the thoracic chamber in the dorso-ventral axis

Audio Explanation:


(1) Read page 270, XI NCERT

 

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Volume of air that will remain in the lungs after a normal expiration is about:

1. 1200 ml

2. 2300 ml

3. 4600 ml

4. 5800 ml

Audio Explanation:


Answer: 2

This is FRC. Read page 272, XI NCERT

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The partial pressure of oxygen is equal

1. Atmospheric air and Alveoli

2. Alveoli and Oxygenated blood

3. Alveoli and Deoxygenated blood

4. Deoxygenated blood and Tissues

Audio Explanation:


(4) Read page 272, Table 17.1, XI NCERT.

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The solubility of carbon dioxide is about times higher than that of oxygen across the respiratory membrane.

1. 20-25

2. 25-50

3. 125-150

4. 200-250

Audio Explanation:


(1) Read page 273, XI NCERT.

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