was sind gene — what does this mean exactly?

Genes are the fundamental units of heredity, composed of DNA (deoxyribonucleic acid). They contain the instructions for making proteins, which control nearly all functions in the body – from enzymes to structural proteins to signaling molecules. Humans have approximately 20,000–25,000 genes, arranged on chromosomes in the cell nucleus. The sequence of DNA bases (A, T, C, G) determines which proteins are produced. Variations in these sequences (called SNPs or mutations) can alter protein activity and thus influence health, metabolism, and disease risk. It is crucial to understand that genes are not deterministic. Environment, diet, lifestyle, and epigenetics modulate whether and how strongly a gene is expressed. In personalized medicine (e.g., at MyBody-X), certain gene variants are analyzed to provide hints about individual needs – but the effects are usually small and not decisive on their own. Genetics is complex; a single gene rarely determines a trait. The evidence for many gene–nutrient interactions is still limited. Therefore, genetic tests should always be considered as part of a holistic approach.