There may be many forms of a single gene. Each such form is called an allele
Answer:
Ozone
Explanation:
Ozone is considered a pollutant in the troposphere, but in the stratosphere it is essential to life on earth because it absorbs biologically harmful UV radiation. The mesosphere and the thermosphere are two additional atmospheric layers above the stratosphere.
Answer:
light reflection
Explanation:
often seen by sunlight to windows