2 is the answer I THINK look at other ones first
Ive heard that the large amounts of dust hindered the sun and growth of plants
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
