Final answer:
Somatic hypermutation refers to the process where DNA sequence alterations occur at a high rate within somatic cells, particularly B cells, resulting in enhanced antibody diversity. These mutations are non-heritable and distinct from germline mutations, which can be passed to offspring. Somatic mutations may affect individual health, potentially leading to cancer if many mutations accumulate.
Step-by-step explanation:
What is Somatic Hypermutation?
Somatic hypermutation is a biological process where the DNA sequence of a somatic cell (a non-reproductive cell) is deliberately altered at a high rate. Occurring predominantly in B cells of the immune system, this mutation affects the variable regions of antibody genes and serves to increase the diversity of antibodies available to fight pathogens. The mutations introduced during somatic hypermutation can lead to antibodies with a higher affinity for their antigen, which enables a more effective immune response.
While somatic hypermutations operate within somatic cells, they are contrasted with germline mutations, which occur in gametes—eggs and sperm—and can be passed down to offspring. Somatic mutations are confined to the cell in which they occurred and its progeny, meaning they cannot be inherited by the next generation, but can influence the health of the organism within its own lifespan. For instance, if many somatic mutations accumulate in a cell, it could lead to uncontrolled cell division, characteristic of cancerous cells.
In terms of location within the body, somatic hypermutations occur within cells other than gametes. A specific example includes the B cells within the lymph nodes and spleen during an immune response. This process differs from point mutations, which change a single nucleotide, and frameshift mutations, which involve the addition or deletion of nucleotides that disrupt the reading frame, potentially affecting proteins synthesized by the cell.