Mutations

Definition

Mutations are changes in the nucleotide sequence of DNA that can lead to alterations in the structure and function of proteins. They can occur spontaneously or due to environmental factors such as radiation or chemicals.

5 Must Know Facts For Your Next Test

1. Point mutations involve a single nucleotide change, which can be silent, missense, or nonsense.
2. Frameshift mutations result from insertions or deletions of nucleotides that shift the reading frame of the genetic code.
3. Mutations can be beneficial, neutral, or harmful depending on their impact on protein function and organismal fitness.
4. Mutagenic agents such as UV light and chemical carcinogens increase the rate of mutations.
5. DNA repair mechanisms like base excision repair and nucleotide excision repair help correct mutations but are not always foolproof.

Review Questions

• What are the different types of point mutations and how do they affect protein synthesis?
• How do frameshift mutations differ from point mutations?
• What role do mutagenic agents play in increasing mutation rates?

Related terms

Genotype:

The genetic makeup of an organism that determines its traits.

Phenotype:

The observable physical or biochemical characteristics of an organism.

DNA Repair:

Processes by which a cell identifies and corrects damage to its DNA molecules.