Week 4- Mutation and Polymorphism Flashcards
How much of DNA is identical b/w individuals?
99.9%
What is a mutation?
Any change in nucleotide sequence or DNA arrangement
What is a genome mutation?
Creates aneuploidy
Alters the number of chromosomes in a cell
Affects 100’s to 1000’s of genes
What is a chromosome mutation?
alter structure of individual chromosome
Affects 100’s of genes
What is a gene mutation?
Alters gene
Range from single nucleotide to millions of bp
What is a mutation that occurs during gamete formation- perpetuated to offspring
Germ-line mutation
What is mutation that creates somatci mosaicism- not transferred to offspring
Somatic mutation
What causes genome mutations?
mis-segregation causing monosomy or trisomy
Why are chromosome mutations rarely perpetuated?
Normally incompatible with survival- usually happens after someone is born
What causes gene mutations?
BP substitution
Insertions
Deletions
What are two mechanisms of gene mutations?
DNA replication errors
Problems during DNA repair
What are the three main classes of types of gene mutation?
Nucleotide substitution
Deletions and Insertions
Dynamic Mutations
What are the types of Nucleotide substitutions?
Missense
Chain termination
RNA processing
What is a point mutation that alters the triple- replaces one aa with another
missense mutation
What are common disorders caused by missense mutations?
Hemoglobinopathies
ex- sick cell anemia
What type of mutation causes a normal codon to become a termination codon?
Chain termination mutation
What is a mutation at an intron/exon boundary that interferes with or abolishes normal RNA splicing?
RNA processing mutation
What is a frameshift mutation?
A small insertion or deletion that is not in a multiple of 3
What are two disorders with large deletions and insertions?
Duchenne MD and alpha thalassemias
Are insertions or deletions more common?
Deletions
What does LINE stand for?
long interspersed nuclear elements
What are some effects of recombination?
Deletion or duplication by recombindation
What is an example of a condition caused by recombination?
Familial Hypercholesterolemia
What are recombination mutations usually due to?
Unequal crossing over
