What is a mutation?

A mutation is defined as a permanent change in the DNA sequence of an organism. This change can occur in various forms, such as a point mutation where a single nucleotide is altered, or larger structural changes that can affect multiple genes. Mutations can arise from various factors, including errors during DNA replication, exposure to certain chemicals, or radiation.

The permanence of a mutation is significant because it can be passed on to subsequent generations if it occurs in the germline cells (sperm or eggs), potentially influencing the evolution of a species over time. Some mutations can lead to new traits that may be beneficial, harmful, or neutral to the organism's fitness in its environment.

In contrast, the other choices refer to concepts related to genetic change but do not accurately describe what a mutation is. For instance, a gradual change in a population typically refers to evolution through processes like natural selection or genetic drift, while a temporary alteration would not constitute a mutation, as mutations are stable changes in the genetic material. Meanwhile, the idea of a selective advantage in all organisms is too broad; not all mutations confer advantages, and whether a mutation provides an advantage often depends on the specific environmental context.