Lecture 8, mutations Flashcards
What different types of mutations are there?
Gene mutations, genome mutations, chromosomal mutations
What categorizes can mutations be divided into based on their expression?
Harmful vs Benefical, Loss of function vs Gain of function, germ line vs somatic mutations
Which mutations are most common?
Genome mutation
What is the mechanism behind genome mutation?
Chromosome mis-segregation, Copy Number Variation (CNV)
What is the mechanism behind chromosome mutartions?
Chromosome rearrengmeant
What is the function of gene mutation?
Base pair substitution
What is a point mutation?
Mutation in a single site of the genome corresponding to a small part or one singular gene
What does transitions vs transversions mean in context of point mutations?
C and T and A and G can bind together becasause they have three and two OH bonds. So it’s much more common for a transition where a C is replaced with a T then a transversion where it would be exchanged with an A for example.
What types of point mutations are there?
Single nucleotide substitution and frameshift mutation single nucleotide substition is the replacemeant of a nucleotide and frameshift mutation is the insertion or deletion of a nucleotide.
What types of mutations can single nucleotide substitution lead to?
A silent mutation where there is no change in the amino acid. Missense mutation where there is a change of amino acid and a nonsense mutation where there is an insertion of a stop codon.
What types of genome mutations are there?
Aneuploidy: chromosome number differ from wild type by one chromosome set, Polyploidy: organisms with more than two chromososome sets Such as triploid (3n) or tetraploid (4n). Common in plants. There is also change in genome structure called copy number variation which involves deletion or copying of certain structures.
What phenotypres can copy number variation give rise to?
Gene dosage effects, gene disruption, position effect and unmasking recessive alleles.
What is a chromosomal mutation?
Compared to genome mutations they are visible under microscope and large disruptions of the chromosome.
What can trigger a chromosomal mutation?
double strand breaks or crossing over repetitive DNA but also radiation.
What types of chromosomal mutations are there?
translocations that can be either balanced if no DNA is lost and they complement each other or unbalanced wich results to extra or missing genes.
What is monogenic vs polygenic deseases?
Monogenic is influenced by one gene and polygenic by multiple. Monogenic diseases can often be tracked in families and are more rare. Polygenic diseases are common and can be strongly influenced by the enviormeant.
What does penetrance and expression mean in case of mutations?
Penectrance is the procentage of indivudals precented with the phenotype that carry that allele. Expression means to which degree it is expressed.
What is the difference between mutations and mutant?
Mutations is the change in genes and mutant is the individual carrying the mutation
