dna damage and mutation Flashcards
one or more two versions of a gene
allele
region of dna that encodes function
gene
specific physical location of a gene or other DNA
locus
difference in DNA sequence among individuals, groups, or populations
genetic polymorphisms
most common type of genetic polymorphisms
Variation at a single base pair
Genetic polymorphism may be the result of chance processes or may have been induced by external agents such as __
viruses or radiation
sources of genetic polymorphism
- single nucleotide polymorphism
- sequence repeats
- insertion
- deletion
- recombination
refers to a difference in DNA sequence among individuals has been shown to just be associated with diseases
genetic mutation
A permanent alteration of a nucleotide sequence of a gene or a change in DNA sequence of the Genome of a particular organism
mutation
the presence of more than one allele at a particular locus in a particular population
variant that is present in at least 1% to 2% of a population
polymorphisms
enumerate the types of DNA polymorphism
- tandem repeats
- short tandem repeats
- single nucleotide polymorphism
- copy number polymorphism
enumerate the types of mutation
- chromosomal mutation
- gene mutation
a sequence of two or more DNA based pairs that is repeated in such a way that the repeats lie adjacent to each other on the chromosome
generally associated with non-coding DNA
tandem repeats
examples of standard repeats
- simple sequence repeats
- microsatellites
- minisatellites
variable tandem repeats are used in?
DNA fingerprinting
very short stretches of DNA that are repeated back to back at various locations throughout the human genome
short tandem repeats
this is helpful in forensic and paternity testing because there are a lot of natural variations
STR short tandem repeats
a polymorphism present at a particular nucleotide side
single nucleotide polymorphism
SNPs may arise from a __ of one nucleotide by another at a polymorphic site. a __ can be transitions.
substitution
the replacement of one purine nucleotide by another purine nucleotide or one pyrimidine by another pyrimidine
transition
a SNP may also be a ___ or __ referred to as INDEL
Single Nucleotide Polymorphism
single base insertion or deletion variant
A variation in which a segment of DNA can be found in various copy numbers in the Genome of different individuals
copy-number polymorphisms
occur in the eggs and sperm and can be passed on to offspring
germline mutation
somatic mutation occur in __ and are not passed
body cells
A change in the structure of a chromosome or where there is a loss or gain part of a chromosome
chromosomal mutations
mutation can be caused by?
- cell division
- exposure to ionizing radiation
- exposure to mutagents
- infections
- virus
chromosomal mutations can be?
- deletion
- insertion
- duplication
- translocation
a chromosomal mutation due to a breakage where a piece of a chromosome is lost
deletion
Chromosome segment breaks up; chromosome segment flip around backwards then segment reattaches
insertion
when a gene sequence is repeated
duplication
Involves 2 chromosomes that are not homologous and part of one chromosome is transferred to another chromosome
translocation
Failure of chromosomes to separate during meiosis and causes the gametes to have too many or too few chromosomes
non-disjunction
associated with physical growth delays characteristic facial features and mild to moderate intellectual disability
what chromosome is affected?
down syndrome
three 21st chromosome
A condition that only affects females wherein a girl is born with only one sex
chromosome, an
__
turner syndrome
X chromosome
this syndrome can cause a variety of medical and developmental problems including short height, failure of the ovaries to develop, and heart defects
turner syndrome
a genetic disorder that affects males it occurs when a boy is born with one or more extra X chromosomes
kleinfelter syndrome
XXY chromosome
this syndrome can cause a male to have some physical traits unusual for males such as weaker muscles, greater height, poor coordination or less body hair and sterility
kleinfelter syndrome
XXY chromsome
change in the nucleotide sequence of a gene; may only involve a single nucleotide, maybe due to copying errors, chemical viruses
gene mutations
a change of a single nucleotide; it includes the deletion, insertion, or substitution of one nucleotide in a gene
point mutation
a mutation which one that does not result in a change of amino acid because of the degeneracy of the genetic code
silent mutation
a substitution that changes according coding for one amino acid to a codon coding for a different Amino acid
missense mutation
mutation results in an amino acid that is similar in function and properties to the original amino acid
conservative missense mutation
alteration in nucleotide caused the formation of a completely different kind of amino acid in the chain
non-conservative missense mutation
a mutation in which a a type of non-synonymous codon change in which a stop codon is formed thereby leading to premature termination of a polypeptide chain and formation of a truncated protein
nonsense mutation
a mutation in which an opposite of the nonsense mutation; a non- synonymous codon change that causes the destruction of a stop codon that were resulting in an extended polypeptide product
read-through mutation
Inserting or deleting one or more nucleotides
frameshift mutation
Changes the “reading frame” like changing the sentence; causes proteins to be built incorrectly
frameshift mutation
exchanges one base for another or a single chemical letter such as switching an A to G
substitution mutation
addition of one or more nucleotide base pairs into DNA sequence
insertion mutation
Spontaneous isomerization of a nitrogen base to an alternative hydrogen-bonding form, possibly resulting in a mutation
tautomeric shifts
it differ by only a single proton shift in the molecule. The shape changes the bonding structure of the molecule and allow the hydrogen bonding with the non- complementary basis in order for automatic shape mainly to permanent base pair changes and mutations
tautomeric shifts
what is the difference between mutation and polymorphism?
the frequency of occurrence
mutation: affects one person
polymorphism: affects a particular population
mutation results from DNA copying mistake during ___
- cell division
- exposure to ionizing radiation
- exposure to mutagens
- infections
