Week 8 - Mutations & Genetic Variation Flashcards
Single Nucleotide Polymorphism
A variation in a single nucleotide in the DNA sequence among individuals of a species. SNPs can be silent, cause disease, or have no effect.
Silent Mutation
A mutation that changes a nucleotide but does not alter the amino acid sequence due to the redundancy of the genetic code.
Missense Mutation
A mutation that results in a different amino acid being incorporated into a protein, which may affect its function.
Nonsense Mutation
A mutation that changes a codon into a stop codon, leading to premature termination of protein synthesis.
Genetic Code
The set of rules by which nucleotide sequences in DNA or RNA are translated into amino acids for protein synthesis.
Nucleotide Insertion
The addition of one or more nucleotides into a DNA sequence, which can lead to a frameshift mutation if not in multiples of three.
Frame Shift Mutation
A mutation caused by insertions or deletions that shift the reading frame of the genetic sequence, often resulting in a completely different and nonfunctional protein.
Codon
A sequence of three nucleotides in mRNA that specifies a particular amino acid or a stop signal during translation.
Chromosomal Mutations
Large-scale genetic changes that affect whole chromosomes or large chromosome segments, including deletions, duplications, inversions, insertions, and translocations.
Deletion
A mutation in which a section of DNA or a chromosome is lost, potentially removing essential genetic information.
Duplication
A mutation in which a segment of DNA or a chromosome is copied and appears twice, potentially altering gene dosage.
Inversion
A chromosomal mutation where a segment of a chromosome is reversed end to end, which may disrupt gene function.
Insertion
The addition of extra genetic material into a DNA sequence or chromosome, which can disrupt gene function.
Translocation
A mutation in which a segment of a chromosome moves to a different location, either within the same chromosome or to a different chromosome.
Transposons and Mutations
“Jumping genes” that can move within the genome, sometimes causing mutations by disrupting or altering gene expression.
Post-Replication Repair
Mechanisms that correct errors in DNA after replication, ensuring genome integrity.
Base Excision Repair
A DNA repair mechanism that removes and replaces a single damaged base.
Nucleotide Excision Repair
A repair mechanism that removes larger DNA lesions, such as thymine dimers caused by UV light.
Phenotype
The observable physical and functional traits of an organism, influenced by genetics and environment.
Genotype
The genetic makeup of an organism, including the specific alleles inherited from its parents.
Alleles
Different versions of a gene that can lead to variations in traits.
Dominant
An allele that expresses its trait even if only one copy is present.
Recessive
An allele that only expresses its trait when two copies are present (homozygous condition).
Environment and Phenotype
The interaction between genetic factors and environmental influences in determining an organism’s traits.
Neutral Mutation
A mutation that does not affect an organism’s fitness or phenotype.
Beneficial Mutation
A mutation that provides an advantage to an organism, potentially increasing survival or reproduction.
Detrimental Mutation
A mutation that negatively affects an organism’s fitness, possibly leading to disease or reduced survival.
Natural Variation
The genetic diversity found within a species due to mutations, recombination, and other genetic factors.
Selection
The process by which certain traits become more or less common in a population based on their effect on survival and reproduction.
Domestication
The process of selectively breeding organisms over generations to enhance desirable traits for human use.
Biodiversity
The variety of life forms within an ecosystem, species, or the entire planet, shaped by genetic variation and environmental factors.
