Final answer:
Hereditary diseases are passed from one generation to another through mutated genes. These mutations can be either dominant or recessive, and while somatic mutations are not hereditary, germline mutations are. Healthy carriers with a family history of genetic disorders can pass the mutated genes to their children.
Step-by-step explanation:
True, hereditary diseases are indeed passed from one generation to the next through mutated genes. Hereditary diseases, such as cystic fibrosis, sickle cell anemia, and Tay-Sachs disease, are caused by mutations in specific genes that can be transmitted from parents to their offspring. These genetic mutations can either be dominant or recessive and may result in the disease being expressed in the children.
Germline mutations are heritable and can be passed down to offspring if they occur in germ cells (sperm or egg). Some germline mutations greatly increase the chances of developing certain diseases, such as the mutations in the BRCA2 gene which heighten the risk of breast cancer. On the other hand, somatic mutations, which occur in non-germ cells, may lead to conditions like cancer but are not inherited.
Mutations that cause hereditary diseases can arise spontaneously or result from environmental factors. A healthy individual, with a family history of a recessive genetic disorder, may carry the mutated gene without being affected by the disease. It's important for such individuals to understand their risk of passing on the disorder to their offspring, which can often be assessed through pedigree analysis rather than direct testing.