Introduction to the human genome Flashcards
_______ + ________ = Disease
genes + environment = Disease
how do strands of DNA pair up ?
in an antiparallel fashion
what direction is DNA replicated in ?
5’ to 3’
where is information held in DNA and how is this held ?
base sequence which is held on sugar-phosphate backbone
When can DNA be damaged and how are they fixed?
during replication
when defected disease occurs
repair mechanisms exist
what order does the cell cycle occur ?
G1
S
G2
M
during the cell cycle what occurs in the S phase ?
DNA synthesis
define mitosis
one diploid parent cell becomes two identical diploid daughter cells
define meiosis
one diploid parent cell becomes four haploid daughter cells
crossing over occurs
gamete formation
Components of RNA
single stranded
ribose sugar
uracil replaces thymine
briefly list the steps of transcription/translation
DNA transcribed to pre mRNA
pre mRNA spliced to mRNA
mRNA translated to protein
protein is modified and moved around cell
how many bases are required to encode 1 amino acid or a stop codon ?
three
examples of sequence variation within a genes
changes in promoter sequence
changes in exon sequence
examples of sequence changes in DNA between genes
SNPs
larger deletions or duplications
What is polymorphism ?
any variation in human genome which has a population frequency >1%
does not cause disease in own right
may predispose to common disease
