Which of the following is NOT a source of genetic variation? crossing over
random lining up of chromosomes in metaphase I
a random assortment of chromatids into daughter cells
duplication of DNA during interphase

thymine. in rna, thymine is replace by uracil

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.

"d.) carbon dioxide and hydrogen sulfide"