Gene Mutations, Transposable Elements, and DNA Repair

These flashcards cover key terms and concepts related to gene mutations, their categories, transposable elements, and DNA repair mechanisms.

Mutation

An inherited change in genetic information, altering the nucleotide sequence of the genome.

Somatic mutations

Mutations that arise in somatic tissues and are not inherited by offspring.

Germ-line mutations

Mutations that arise in cells that produce gametes and can be passed to future generations.

Chromosome mutation

A large-scale genetic alteration affecting chromosome structure or number.

Gene mutation

A small DNA lesion that affects a single gene, resulting in a permanent change in its DNA sequence.

Base substitution

The alteration of a single nucleotide in DNA, leading to different codons.

Frame shift mutation

Mutations caused by insertions or deletions that change the reading frame of a gene.

Repeats expansion

Mutations where the number of copies of a trinucleotide increases in coding areas of DNA.

Missense mutation

A base substitution that results in a different amino acid.

Nonsense mutation

A mutation that converts a sense codon into a stop codon, terminating protein synthesis prematurely.

Silent mutation

A change in DNA sequence that does not alter the amino acid sequence due to redundancy in the genetic code.

Loss-of-function mutation

A mutation resulting in complete gene inactivation or a nonfunctional gene product.

Gain-of-function mutation

A mutation that qualitatively alters the action of a gene, potentially producing new traits.

Suppressor mutation

A genetic change that hides or suppresses the effect of another mutation.

Spontaneous mutations

Mutations occurring under natural conditions due to inherent DNA structure changes.

Induced mutations

Mutations resulting from external factors such as environmental chemicals or radiation.

Mutagen

A substance that induces mutations, causing permanent changes in the genome.

Ames test

A test to determine whether a substance is mutagenic and potentially carcinogenic by observing its effect on bacteria.

Transposable elements

DNA sequences that can move from one location in the genome to another and induce mutations.

DNA repair

Mechanisms that correct changes and errors in the DNA to maintain genomic integrity.

Mismatch repair

A DNA repair system that fixes incorrectly matched base pairs.

Nucleotide excision repair

A DNA repair mechanism that removes bulky lesions that distort the DNA double helix.

Deamination

The spontaneous loss of an amino group from a base, which can lead to mutations.

Depurination

The spontaneous loss of a purine base from a nucleotide, leading to apurinic sites that can insert incorrect bases.

Mutation rate

The number of mutations per biological unit, varying among genes and species.

Gene therapy\n\n

A technique that modifies a person's genes to treat or prevent disease, potentially correcting genetic disorders by inserting, altering, or removing genes within the patient's cells.\n\n

CRISPR-Cas9\n\n

A revolutionary gene-editing technology that allows for precise modifications in the DNA of living organisms, enabling researchers to add, remove, or alter genetic material at specific locations in the genome.\n\n

Polygenic inheritance\n\n

A type of inheritance where multiple genes influence a trait, leading to a continuous range of phenotypes, such as height or skin color.\n\n

Epigenetics\n\n

The study of changes in gene expression that do not involve alterations to the underlying DNA sequence, often influenced by environmental factors and cellular conditions.\n\n

Oncogene\n\n

A mutated form of a gene that, when aberrantly expressed, has the potential to cause normal cells to become cancerous by promoting uncontrolled cell division.\n\n

Tumor suppressor gene\n\n

A gene that protects a cell from becoming cancerous; when mutated or lost, it can lead to increased cell division and tumor formation.\n\n

DNA sequencing\n\n

The process of determining the exact sequence of nucleotides in a DNA molecule, providing valuable information about genetic code and biomolecular function.\n\n

Pharmacogenomics\n\n

The study of how genes affect a person's response to drugs, aimed at developing effective, safe medications and doses tailored to individual genetic profiles.\n\n

Transgenic organism\n\n

An organism that has been genetically modified to contain a gene or genes from another species, often used for agricultural or medical purposes.\n\n

Biotechnology\n\n

The technological application that uses biological systems, living organisms, or derivatives to develop or create products, improve processes, and enhance lives.