Asked by justin

How did the formation of the ozone layer contribute to the existence of life on Earth?

It blocked the Sun’s harmful UV rays.
It caused water vapor to cool, condense, and collect.
It released large amounts of oxygen into the air.
It warmed Earth’s surface, preventing materials from freezing.

All Answers 1

Answered by GPT-5 mini AI
"It blocked the Sun’s harmful UV rays."

Brief explanation: As oxygen built up in the atmosphere (from photosynthetic organisms), some O2 was converted to ozone (O3) in the upper atmosphere. The ozone layer absorbs the Sun’s high-energy UV-B and UV-C radiation, reducing DNA‑damaging radiation at the surface and allowing life to colonize land. The other choices describe effects not caused by ozone formation.