Determine the dna sequence from which this mrna sequence was transcribed

the convention from converting a DNA code to mRNA code is; A matches U,T matches with A,G matches with C and C matches with G

following the convention

DNA:ATGCGCAGTTATTGCGAT

mRNA:UACGCGUCAAUAACGCUA

I hoped this helped you

i am going to guess that it is co2.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).