Which structure is not concerned with breathing in a frog?

Arrange the given steps of the respiration mechanism in the order they occur in the human body:
$I.$ Breathing or pulmonary ventilation
$II.$ Diffusion of $O_2$ and $CO_2$ between blood and tissues
$III.$ Transport of gases by blood
$IV.$ Utilisation of $O_2$ by cells
$V.$ Diffusion of $O_2$ and $CO_2$ across the alveolar membrane
Choose the correct option.

If a large number of people are enclosed in a room,then

Which of the following statements are not correct?
$I.$ Diffusion membrane is made up of $3$ layers
$II.$ Solubility of $CO_{2}$ in blood is higher than $O_{2}$ by $25$ times
$III.$ Breathing volumes are estimated by spirometer
$IV.$ High $H^{+}$ in blood favours oxygen dissociation
Choose the correct option

$I.$ $pO_2$ is the major factor which affects the binding of $CO_2$ with haemoglobin.
$II.$ $pCO_2$ is low and $pO_2$ is high in tissues.
$III.$ $RBC$ contains a very high concentration of carbonic anhydrase.
$IV.$ Every $100 \; mL$ of deoxygenated blood delivers approximately $4 \; mL$ of $CO_2$ to alveoli.
Select the combination of right statements.

At high altitudes,the number of red blood cells in humans: