Hello, sorry for the late response.
DNA is shaped like a double helix or a twisted ladder with two sugar-phosphate backbones and rungs made of paired chemicals (A-T and C-G). The order of these rungs is the unique code that determines your traits.
![](https://biology-forums.com/gallery/43/medium_671907_17_06_21_5_50_19.png)
When a cell needs to divide, DNA replicates. The enzyme DNA helicase break the hydrogen bonds holding the rungs together, unwinding the ladder. DNA polymerase then reads the exposed bases on the single strand and attracts complementary nucleotides (the building blocks) that match according to the A-T and C-G rule. This process ensures an accurate copy is built. Finally, DNA ligase seals the gaps between the newly added nucleotides, creating a complete new DNA strand. This ensures both new cells get a perfect copy of the DNA code.
![](https://biology-forums.com/gallery/47/medium_33_23_06_11_4_16_34.jpeg)
DNA expression is how your cells use this code. Specific sections of DNA called
genes contain instructions for building proteins. These proteins determine your physical characteristics like eye and hair color, and even influence some personality traits. Different combinations of genes in this code create the incredible variation we see in people.