Question

Why would a mutation in a somatic cell of a multicellular organism escape detection?

Short answer

Answer: A mutation in a somatic cell might escape detection due to limited impact, functional redundancy, cellular compartmentalization, apoptosis, and phenotypic buffering. These factors can result in the mutation having no observable effect on the organism's phenotype or causing damage that is confined to a single organism and not passed on to the next generation, thus reducing the chances of detection.

Step-by-step solution

Understand Somatic Cells

Somatic cells are the body cells that make up the majority of a multicellular organism's tissues and organs. These cells undergo mitosis for growth and repair within the organism. In contrast, germ cells are the reproductive cells that undergo meiosis, resulting in the formation of gametes (sperm and egg cells) used in sexual reproduction.

Understand Mutations

Mutations are changes that occur in the DNA sequence within a cell. These can be caused by various factors, such as errors during DNA replication, exposure to environmental factors, or during DNA repair. Mutations can be neutral, beneficial, or harmful to the organism, depending on the gene affected and the nature of the change.

Examine How Mutations Are Detected

A mutation can be detected through various testing methods and checks in place within the organism. One significant mechanism is the DNA repair system, which identifies and corrects damages to the DNA. Additionally, mutations can be detected when they lead to noticeable changes in the organism's phenotype (physical characteristics) or when they cause health issues.

Explain Why Somatic Mutations May Escape Detection

A somatic mutation may escape detection for several reasons: 1. Limited impact: Since somatic mutations occur in body cells and not in germ cells, they are not passed on to the next generation. This limits the impact of the mutation, as it remains confined to a single organism rather than affecting the entire population. 2. Functional redundancy: Some genes have multiple copies in the genome, allowing other copies to compensate for a mutation in one copy. This may result in the mutation having no observable effect on the organism's phenotype. 3. Cellular compartmentalization: Multicellular organisms have specialized tissues and organs, with each cell type performing specific functions. A mutation in one somatic cell may not be relevant or harmful to other cells in the organism, reducing the chances of detection. 4. Apoptosis: Cells have mechanisms to trigger programmed cell death (apoptosis) if they sense DNA damage or mutations. This may prevent the mutated cell from causing harm to the organism, eliminating the need for detection of the mutation. 5. Phenotypic buffering: Some mutations may not drastically alter an organism's phenotype due to the complex interactions between genes and environmental factors. These mutations may remain undetected as they do not cause a noticeable change in the organism.