Practice free Breathing and Exchange of Gases (Zoology) NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
In the alveoli, which of the following conditions would favour the formation of oxyhaemoglobin?
The NCERT states, 'In the alveoli, where there is high $pO_2$, low $pCO_2$, lesser $H^+$ concentration and lower temperature, the factors are all favourable for the formation of oxyhaemoglobin.'
Under normal physiological conditions, how much $O_2$ can 100 ml of oxygenated blood deliver to the tissues?
The NCERT mentions, 'Every 100 ml of oxygenated blood can deliver around 5 ml of $O_2$ to the tissues under normal physiological conditions.'
The sigmoidal shape of the oxygen dissociation curve is primarily due to:
While not explicitly stated in the provided text as the reason for the sigmoidal shape, the cooperative binding of oxygen to haemoglobin (where binding of one $O_2$ molecule increases the affinity for subsequent $O_2$ molecules) is the well-known biological explanation for the sigmoidal pattern of the oxygen dissociation curve. The text only asks to 'suggest any reason for its sigmoidal pattern' as an exercise, implying it's a concept to be understood.
Which of the following factors would cause a shift of the oxygen dissociation curve to the right?
A shift to the right indicates decreased affinity of haemoglobin for oxygen, favouring dissociation. The NCERT states that high $pCO_2$ and high $H^+$ concentration (which corresponds to low pH) favor dissociation in tissues. Therefore, an increase in $H^+$ concentration would cause a right shift.
What percentage of $O_2$ is transported by RBCs?
The NCERT states, 'About 97 per cent of $O_2$ is transported by RBCs in the blood.'
Which component of blood primarily carries oxygen to the cells?
The NCERT mentions, 'About 97 per cent of $O_2$ is transported by RBCs in the blood.' Erythrocytes are Red Blood Cells (RBCs).
Aside from partial pressure of $O_2$, what other factors can interfere with the binding of oxygen with haemoglobin?
The NCERT states, 'Partial pressure of $CO_2$, hydrogen ion concentration and temperature are the other factors which can interfere with this binding.'
The statement 'O$_2$ gets bound to haemoglobin in the lung surface and gets dissociated at the tissues' implies:
This statement directly reflects the dynamic nature of oxygen-haemoglobin binding, where affinity changes based on local conditions ($pO_2$, $pCO_2$, H+ concentration, temperature). This is the core concept explained by the oxygen dissociation curve and its shifts.
If the oxygen dissociation curve shifts to the left, it indicates:
A leftward shift of the oxygen dissociation curve signifies that for a given $pO_2$, haemoglobin is more saturated with oxygen, meaning it has a higher affinity for oxygen and holds onto it more tightly.
Which of the following organisms primarily uses simple diffusion over their entire body surface for the exchange of O2 and CO2?
As per the NCERT text, 'Lower invertebrates like sponges, coelenterates, flatworms, etc., exchange O2 with CO2 by simple diffusion over their entire body surface.'
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