Question

Why is oxygen gas important to life on earth?

1) It is used by plants to undergo photosynthesis.
2) It plays a role in the formation of banded-iron rocks.
3) It is a source of heat at earth's surface.
4) It provides protection from harmful ultraviolet radiation from the sun.

Answer 1

Oxygen gas is essential for life on Earth as it forms the ozone layer, which protects organisms from harmful UV radiation, allowing life to thrive on land and in the ocean.

Step-by-step explanation:

Oxygen gas is crucial to life on Earth because it plays a pivotal role in forming the ozone layer, which is essential in protecting living organisms from the harmful effects of the Sun's ultraviolet (UV) radiation. The free oxygen produced by photosynthesis around 2.4 billion years ago accumulated in our atmosphere and interacted with sunlight to produce ozone. This ozone, consisting of three atoms of oxygen per molecule, formed a protective layer in the stratosphere, absorbing most of the dangerous UV radiation.

If this protective layer were not in place, UV radiation could cause severe cell damage, leading to an increase in skin cancers, eye damage, and harm to organisms such as plankton, drastically affecting the biosphere. The stratospheric ozone, therefore, is vital for life to thrive not only in the oceans but also on land masses by shielding them from UV radiation.