What are mutations that occur at some point during a person's life and are not inherited from parents called?

Somatic mutations refer to changes in the DNA sequence that occur in non-reproductive cells. These mutations can arise at any point during a person's life due to various factors such as environmental influences, exposure to radiation, or errors during DNA replication. Since somatic mutations are not present in the germ cells (sperm and eggs), they are not inherited by offspring, and therefore, are limited to the individual in which they occur. This distinction is essential in understanding genetics and how certain mutations can lead to diseases or conditions that affect just one individual rather than being passed down through generations.

In contrast, germline mutations occur in the reproductive cells and can be inherited, while inherited mutations imply a direct pass from parent to offspring. Chromosomal mutations involve large segments of DNA and are typically more severe than the single-gene mutations that somatic mutations often represent.