genetics Flashcards
what can be used to recognise a chromosome
Banding pattern
Length
The position of the centromere
what can be used to analyse chromosomes (4)
FISH (specific)
Array CGH (general)
PCR
Next Generation Sequencing (NGS)
what is a balanced abnormality
all genes present just in different places
what is an unbalanced abnormality
has missing or additional material
what is an aneuploidy
whole extra or missing chromosome
what is trisomy 21
down syndrome
what is trisomy 18
edwards syndrome
what is a robertsonian translocation
two chromsomes get stuck together
what is a reciprocal translocation
when segments of material are exchanged between different chromosomes
what is penetrance
the likelihood of having a disease if you have the mutation
what is mosaicism
when different cells have different genetic material
what do oncogenes do
make cells divide
what do tumour suppressor genes do
stop cells dividing
when does methylation usually occur
on cytosine bases just before guanine
what does methylation cause
modification of histones that then stop transcription
