A Level Biology Practice Exam

What is a mutation?

1. A process that stabilizes genetic material

2. A random error during DNA replication

3. A change in the genetic material that may affect phenotype

4. A technique used in genetic engineering

The correct answer is: A change in the genetic material that may affect phenotype

A mutation is defined as a change in the genetic material of an organism, which can lead to alterations in traits or the phenotype. This change can occur in various ways, such as through substitutions, insertions, or deletions of nucleotides in the DNA sequence. Mutations can be spontaneous or induced by external factors, and their impact on phenotype can vary from benign to detrimental or beneficial, depending on the nature of the change and the environment. Understanding mutations is crucial because they are a primary source of genetic diversity, which is essential for evolution and adaptation. In some cases, mutations can lead to new traits that may provide a selective advantage or disadvantage, influencing the survival and reproduction of organisms. In contrast, other options discuss processes or techniques that do not inherently define a mutation. A process that stabilizes genetic material describes mechanisms like repair or homeostasis, while random errors during DNA replication refer specifically to a mechanism that can lead to mutations but does not encompass the broader concept of a mutation itself. Meanwhile, genetic engineering involves manipulating genetic material but does not define a mutation. Thus, the most accurate description of a mutation and its implications is that it is a change in the genetic material that may affect phenotype.