Which of the following genotype(s) would be considered 'purebred'
a. homozygous dominant
b. homozygous recessive
c. heterozygous
d. both a and b
e. codominant

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.