Get ahead with a $300 test prep scholarship
| Enter to win by Tuesday 9/24
BB 1035 Chapter XV: Gene Mutation and Molecular Medicine
Terms in this set (27)
What is an allele?
Different versions of a gene
2 major types of mutations
Point - addition/substitution/subtraction of single nt
Chromosomal - Whole DNA molecules break/rejoin
5 types of point mutations
Purine substituted for another purine
Purine substituted for pyrimidine or vice versa
One aa substituted for another
Base substitution results in formation of stop codon
Addition/subtraction of 1 or 2 nt (cannot be change in multiple of 3 nts)
4 types of chromosomal mutations?
Removal of one part of genetic material
homologous chromosomes break at diff. positions and reconnect to wrong partners
- One has deleted segment
- Other has two copies of same segment
DNa becomes "flipped"; runs opposite direction of original orientation
Segment of chromosome breaks off and becomes attached to diff. chromosome
What is an SNP and what does it stand for?
SNP = Single nucleotide polymorphism
Inhertied variations involving a single nt base (point mutation)
What does STR stand for and what is it?
STR - Short tandem repeats
Short, repetitive DNA sequences that occur side by side on chromosomes (**USUALLY NONCODING REGIONS)
Doesn't usually affect protein function
B/w LOF and GOF, which tends to be recessive/dominant?
LOF usually recessive
GOF usually dominant
Altered gene product possesses reduced level of activity
Altered gene completely loses function
Altered gene has increased level of activity
Altered gene has entirely new activity
Both GOF and LOF; tends to be dominant
- GOF b/c new function to bind to itself
- LOF b/c binding causes inhibition
Somatic vs. germ line mutations?
somatic - passed to daughter cells
germ line - passed on to sexually produced offspring
What are considered "hot sports" for mutations?
Where cytosine has been methylated to 5'-methylcytosine
Diseases caused by interactions of many genes and proteins w/ environment
- much more common than single-gene mutated disease
What two things are used for DNA fingerprinting?
SNPs and STRs
SNP - single nucleotide polymorphism
STR - short tandem repeat
Mutant gene replaced w/ normal gene