What is a mutagen?
A physical and chemical environmental agent that can increase the frequency of mutation in organisms
Mutagens can lead to changes in DNA that may result in mutations.
Define mutation.
Changes in DNA that persist
Mutations can occur due to errors during DNA replication or exposure to mutagens.
Errors during DNA replication are often repaired by _______.
enzymes
These enzymes help maintain the integrity of the genetic material.
What are frameshift mutations?
Mutations that occur when one or more nucleotides in a DNA sequence are either inserted or deleted
This type of mutation can significantly alter the resulting protein.
What causes point mutations?
The substitution of one nucleotide for another
Point mutations can lead to various types of mutations, including silent, nonsense, and missense mutations.
Define silent mutation.
A base substitution in an altered codon corresponds to the same amino acid
Silent mutations do not affect the protein produced.
What is a nonsense mutation?
A base substitution that corresponds to a stop signal
This type of mutation can lead to premature termination of protein synthesis.
Define missense mutation.
A base substitution that corresponds to a different amino acid
Missense mutations can affect protein function depending on the role of the altered amino acid.
What is gene translocation?
A chromosome segment moves to a nonhomologous chromosome
This can lead to genetic disorders or cancer.
What occurs during gene duplication?
Homologous chromosomes do not align properly during meiosis; one chromosome has two copies of a gene or genes
Gene duplication can contribute to genetic diversity.
Define gene inversion.
Genes on chromosomes switch places
This can disrupt gene function and regulation.
What are chromosomal aberrations?
- Deletion
- Duplication
- Inversion
- Translocation
These changes can lead to significant genetic disorders.
What do mutations create in terms of genetic variation?
New alleles with small differences in DNA sequences
This contributes to the diversity of traits in populations.
How do meiosis and sexual reproduction affect genetic variation?
They combine different alleles in new ways
This process increases genetic diversity within a population.
