Oxygen and Carbon dioxide

[sonalidmg]

Oxygen and carbon dioxide are present in air.OXYGEN IS SUPPORTER OF COMBUSTION AND CARBON DIOXIDE extinguishes the fire.Also they are essential for animals and plants life.
1) If the percentage of oxygen in the air increases then what will happen to our life?
2) if the percentage of carbon dioxide in air increases then what change will be seen in plants?

[DaThinker]

i heard an answer to your first queston some time ago. I was told if the percentage of oxygen in the air was around 1% lower we would die of oxygen starvation, and that if it was about 1% higher then we would become highly flamable. so id say that makes us pretty lucky as for co2 it is a greenhouse gas that although being vital for photosynthesis in plants, increases the temprature of the atmosphere if you google venus where co2 ran wild in the past you will see that the results are not particularly good for anything living. I hope this helps.