NEET BIOLOGY

Detailed explanation-1: -Concentrations of 12 to 16 percent oxygen cause tachypnea (increased breathing rates), tachycardia (accelerated heartbeat), and impaired attention, thinking, and coordination (e.g., Ex. 25-4), even in people who are resting.

Detailed explanation-2: -Effects of exposure to low oxygen concentrations can include giddiness, mental confusion, loss of judgment, loss of coordination, weakness, nausea, fainting, loss of consciousness and death.

Detailed explanation-3: -When there is a decrease in the concentration of oxygen in the blood, the breathing rate increases. Breathing rate and breathing volume increase, the blood pressure increases, the heart rate increases, and kidney bicarbonate production ( in order to buffer the effects of blood acidosis), occur.

Detailed explanation-4: -During exposure to 15% oxygen there was a reduction in the proportion of time spent in regular breathing pattern and a 3.5-fold increase in the proportion of time spent in periodic apnoea (P < 0.001).