Term
| how many genes / % and base pairs in human DNA |
|
Definition
| 20-25,000 genes = 1.5% DNA, 3 billion base pairs |
|
|
Term
| DNA sequences in the genome can be classified as (3) |
|
Definition
| 1. single copy DNA (>50%), 2. repetitive DNA (<50%) = satellite and dispersed, 3. mitochondrial DNA (non-nuclear circular DNA from mom; majority of mito proteins are made in nucleus) |
|
|
Term
| 1.5% of DNA that codes for proteins is what kind of DNA |
|
Definition
| single copy DNA; remaining single copy DNA is found in introns and in between genes (some codes for intermediate forms of genes that don't function) |
|
|
Term
| t/f repetitive DNA is evenly dispersed throughout the genome |
|
Definition
|
|
Term
| what is repetitive DNA important for |
|
Definition
| maintaining chromosome structure; important source of variation among individuals |
|
|
Term
|
Definition
| LINES and Alu; scattered across entire genome |
|
|
Term
|
Definition
| repetitive. alpha-satellite, mini-satellite, micro-satellite; clustered together rather than scattered like dispersed repetitive is |
|
|
Term
| LINEs and Alu have what in common, other than being repetitive |
|
Definition
| they've both been implicated in genetic disease. some can generate copies of themselves and integrate elsewhere in the genome = insertional inactivation of a gene |
|
|
Term
|
Definition
| contribute to proper centromere functioning; often are chromosome-specific, so FISH can use them to detect aneuploidy |
|
|
Term
|
Definition
| used in forensics and paternity testing (highly polymorphic among individuals) |
|
|
Term
|
Definition
| short tandem repeats = STRs. most common is the CA repeat. also highly polymorphic and used for forensics and diagnostic testing |
|
|
Term
| genome mutation / example |
|
Definition
| affects the number of chromosomes / missegregation during meiosis = most common mutation in humans = one with 3 and one with 1 (copy of a chromosome) (instead of the normal 2). also common in cancers = acquired trisomies |
|
|
Term
|
Definition
| alters the structure of individual chromosomes. often found in cancer cells or are incompatible with survival or normal reproduction |
|
|
Term
| gene mutation / occurs when / 4 types |
|
Definition
| alters individual genes / errors in DNA replication; mutations from failure to correctly repair DNA damage / nucleotide substitutions, insertions, deletions, tandem repeat expansions |
|
|
Term
| types of nucleotide substitutions |
|
Definition
| (point mutations): silent, missense, nonsense, regulatory element, RNA processing mutations |
|
|
Term
| mutations occurring in silent regions of genome (introns etc.) are called |
|
Definition
| silent mutations. double meaning hah! |
|
|
Term
| hemoglobinopathies are usually |
|
Definition
| missense mutations (sickle cell = Glu > Val) |
|
|
Term
|
Definition
| point mutation which results in a premature stop codon = truncated and usually non-functional protein (translation stops prematurely) |
|
|
Term
| regulatory element mutation |
|
Definition
| affects binding of RNA polymerase to the promoter, or of other transcriptional activators or inactivators to their respective binding sites. results in altered production of mRNA and protein |
|
|
Term
|
Definition
| create or destroy signals for splice sites. leads to improperly processed mRNA |
|
|
Term
|
Definition
| substitution of one purine for another purine, or of one pyrimidine for another pyrimidine |
|
|
Term
|
Definition
| replacement of a purine for a pyrimidine or vice versa |
|
|
Term
| why are there more transitions than transversions? |
|
Definition
| many cytosine residues are methylated (major form of DNA modification), specifically when they're located immediately 5' to a guanine. spontaneous demethylation to thymidine = "hotspot" for mutation |
|
|
Term
|
Definition
| autosomal dominant mutation in FGFR3 gene. G>A point mutation = glycine>arginine substitution |
|
|
Term
| when do insertions/deletions alter a protein |
|
Definition
| when they occur in the coding sequence |
|
|
Term
|
Definition
| insertion/deletion not in a multiple of three; typically results in early stop codon |
|
|
Term
| tandem repeat expansion disorders (5) |
|
Definition
| fragile x syndrome (elongated adult face, big ears), huntington's, spinocerebellar ataxias, friedrich's ataxia, myotonic dystrophy |
|
|
Term
|
Definition
| natural genetic variability; single nucleotide differs between paired chromosomes in a person or between members of a species = bi-allelic marker |
|
|
Term
| genetic signature profile |
|
Definition
| can be created by a person's SNP pattern >>> personalized medicine |
|
|
Term
|
Definition
| can link certain SNP profiles to disease; MS = HLA-DRB1 locus on chromosome 6 |
|
|
Term
| t/f genes are distributed unevenly throughout the genome |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| is actually scrap-pile DNA; we don't know what it's good for, but without it we might be fucked |
|
|
Term
| single gene diseases are _% of diseases in general population |
|
Definition
| 1%, and 10% in hospitalized children |
|
|
