Mutations_Flashcards
What are mutations?
Alterations in the genetic information within DNA or RNA sequences.
What are the two dynamic classifications of mutations?
Dynamic (linked to mutation copy number) and static.
How are mutations classified by size?
As point mutations or chromosomal mutations.
What do point mutations affect?
A small number of nucleotides within a single gene.
What do chromosomal mutations affect?
A larger number of nucleotides and can involve loss or gain of chromosomes (e.g., trisomy, monosomy).
What are the two main causes of mutations?
Spontaneous mutations and induced mutations.
What causes spontaneous mutations?
Uncorrected errors during DNA replication or mistakes by DNA repair systems.
Why is the frequency of spontaneous mutations typically low?
Due to efficient DNA repair enzymes.
What are induced mutations caused by?
Exposure to mutagens.
Name examples of mutagens.
Ionizing radiation (X-rays, UV radiation) and some viruses.
How does mutation location affect its impact?
It depends on whether the mutation occurs in coding, regulatory, splicing, or polyadenylation sequences.
What are potential effects of mutations?
Prevent protein production, alter protein expression levels, or alter protein function.
What determines the phenotypic outcome of a mutation?
The mutation’s position within the DNA sequence.
What are germ cell mutations?
Mutations in germ cells (sperm or egg) that are hereditary and passed to offspring.
Do germ cell mutations affect the individual carrying them?
No, they do not.
What are somatic cell mutations?
Mutations in somatic cells that affect the individual but are not hereditary.
Are somatic cell mutations passed on to offspring?
No, they are not.
What are restriction enzymes?
Proteins from bacteria that cut DNA at specific sites.
What technique uses restriction enzymes?
Restriction fragment length polymorphism (RFLP).
What is the purpose of RFLP?
To analyze variations in DNA sequences.
How does RFLP work?
DNA is digested into fragments using restriction enzymes, then separated by size via gel electrophoresis.
What separates DNA fragments in RFLP?
Gel electrophoresis based on fragment size.
What is agarose gel electrophoresis?
A technique to separate nucleic acid fragments (DNA/RNA) by size.
How does DNA migrate in agarose gel electrophoresis?
Negatively charged DNA moves toward the positive end under an electric current.
What determines the speed of DNA migration in agarose gel?
Smaller fragments migrate faster.
How are DNA bands visualized in agarose gel electrophoresis?
Under ultraviolet (UV) light.
What is the estimated mutation rate in humans?
Between 10^-4 and 10^-6 per gene per generation.
How many nucleotide mutations occur in each human gamete?
Around 30 mutations.
What is an example of a base substitution mutation?
Substituting an A-T base pair with a G-C base pair.
In which DNA regions can mutations occur?
Coding sequences, regulatory sequences, splicing sequences, or polyadenylation sequences.
