human chromosomes 23 + x, y structures made of protein and a single molecule of dna - closeup view 3d

acgt acid acids adenine backbone background base biochemistry cell chain chloroplast chromosome cloning containing cytosine deoxyribonucleic dna double embryo evolution gene genes genetic genome guanine helical helix hereditary human illustration long map mitochondria mitochondrion molecular molecule mutation nitrogen nitrogenous nuclei nucleic nucleobases pairs phosphate polynucleotide purines pyrimidines replication ribonucleic ribose rna sequencing spiral stem structure thymine