Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic. However, when rain combines with sulfur dioxide or nitrogen oxides—produced from power plants and automobiles—the rain becomes much more acidic. Typical acid rain has a pH value of 4.0.
Mitosis creates two identical daughter cells that each contain the same number of chromosomes as their parent cell. ... These new combinations result from the exchange of DNA between paired chromosomes. Such exchange means that the gametes produced through meiosis exhibit an amazing range of genetic variation.
https://www.nature.com/scitable/topicpage/replication-and-distribution-of-dna-during-meiosis-6524853
C is a combustion reaction
