What are the functions of hemoglobin and chlorophyll?

At sea level,the blood of individuals contains approximately $5$ million red blood cells per cubic millimeter. However,individuals living at an altitude of $5400$ meters have $8$ million red blood cells per cubic millimeter. Why does this increase occur?

Match Column-$I$ and Column-$II$ with respect to processes involved in respiration with their explanation:

Column-$I$	Column-$II$
$i$. Cellular respiration	$a$. Exchange of gases $O_2$ and $CO_2$ between blood and tissue cells.
$ii$. Breathing	$b$. Physical process of gaseous exchange between atmospheric air and lungs.
$iii$. Internal respiration	$c$. Gaseous exchange between alveolar air and blood capillaries.
$iv$. External respiration	$d$. Food is oxidized and $ATP$ is generated.

After fast running,a man has a fast heartbeat,a slow pulse,and shallow breathing. In such conditions,he has:

Select the incorrect sentence for respiration.

If a man from the sea coast goes to the Everest peak,then: