Here's why:
* Same Basic Structure: DNA is composed of a double helix structure, made up of nucleotides (adenine, guanine, cytosine, and thymine) linked together by a sugar-phosphate backbone. This structure is consistent across all eukaryotic organisms, from humans to plants to fungi.
* Genetic Information: DNA contains the genetic code, a sequence of these nucleotides that determines an organism's traits and characteristics. This code is passed down from generation to generation, ensuring the continuity of life.
While some variations in DNA sequences can exist between different species, the underlying structure and function remain the same in all eukaryotic organisms.
