7+8 Molecular genetics Flashcards
Which direction is DNA and RNA synthesised?
5’ to 3’.
How many Mbp are there in the human genome?
How many coding genes?
% of genes that are non-coding?
3,000.
20,000.
>90%.
Differentiate between transcription and translation:
Transcription: copying into RNA.
Translation: turning RNA into protein.
How can axons be alternatively spliced?
Exon skipping.
Mutually exclusive exon choice.
What are pseudogenes?
Old genes that are now non-functional.
Interfere with medical diagnostics.
What are processed genes?
Creation?
Unusual example.
Intronless copies of other genes, usually far away from parent.
Created by reverse transcription and integration.
Most non-functional - except PGK2.
What is satellite DNA?
Large blocks of repetitive DNA sequences.
Mainly at centromeres + heterochromatic regions.
What is alphoid DNA?
A type of satellite DNA found at centromeres. Has chromosome specific sequence variation. Required for centromere assembly.
Give an example of an interspersed repeat:
Alu repeat.
5% of the genome.
Dispersed by retrotransposition.
What types of mutation do Duchenne muscular dystrophy and Charcot-Marie-Tooth disease result from?
DMD: deletion.
CMT: duplication.
What is the genetic mutation responsible for Haemophilia A?
F8C gene on Xq28 is grossly rearranged via a u-bend.
How many people does a mutation have to occur in to be polymorphism?
1%.
What does a nonsense mutation result in?
Truncation.
What inheritance pattern does a loss of function mutation usually show?
Recessive.
What inheritance pattern does a gain of function mutation usually show?
Dominant.
