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Cytogenetics
Question | Answer |
---|---|
What does the first number in the chromosome nomenclature represent? | The chromosome number |
What does P represent in the chromosome nomenclature | Short arm |
What does Q represent in the chromosome nomenclature? | Long arm |
What is monosomy? | Only having one chromosome from a homologous chromosome pair |
What is trisomy? | Having three chromosomes from a homologous pair |
What is trisomy 21? | Down syndrome |
What is Edwards syndrome? | Trisomy 18 |
What us turners syndrome? | Monosomy of the sex chromosomes - XO |
What is (incl. appearance) klinefelters syndrome? | Trisomy of the sex chromosome XXY - phenotypically male |
What is a duplication structural aberration? | Gene from one homologous chromosome joins to the other |
What is an inversion structural aberration? | A section is broken from a chromosome and put back in, in the reverse direction |
What is a deletion structural aberration? | A section of the chromosome is deleted |
What is a translocation structural aberration? | A section of the chromosome is broken and replaced on a non-homologous chromosome |
What gene is responsible for sex determination? | SRY gene |
In male, what gonadal duct degerates? | Müllerian duct |
What causes the Müllerian duct to degenerate? | Testosterone |
In females, what gonadal duct degenerates? | Wolfian duct |
What cells produce testosterone? | Leydig cells |
What cells produce anti-mullerian hormone (AMH)? | Serotoli cells |
If males are castrated early, and AMH is not produced. What happens? | Develop as a female |
What technique can be used to detect translocation? | Fluorescent in-situ hybridisation (FISH) |
How many hydrogen bonds between A and T? | 2 |
How many hydrogen bonds between G and C? | 3 |
By what method does DNA replicate? | Semi-conservative hypothesis |
What unwinds the DNA in DNA replication? | DNA helicase |
What enzyme is responsible for making the new DNA strand? | DNA polymerase |
Before DNA polymerase can act, primer sequences are needed to be added. What enzyme is responsible for this? | RNA Primase |
On the lagging strand, primer sequences are needed to be added frequently. What are antlers name for these primer sequences? | Okazaki fragments |
What do single stranded binding (SSB) proteins do? | Prevent the re-winding of DNA |
What is the purpose of topoisomerase? | Nicks the DNA to release tension |