Cellular Genetics Flashcards
Aneuploidy
Irregular number of chromosomes
Klinefelter syndrom
XXY, causes infertility and small testes
Turner syndrom
X, not adolescent growth spurt
XYY syndrome
Asymptomatic
Autosomal recessive definition and example
Non XY and recessive allele Cystic fibrosis
Autosomal dominant (e.g. huntington’s disease)
How genetics causes hungtinton’s disease
Dominant allele, Huntington’s disease
Huntington gene is a tandem repeat of CAG.
Tandem repeat polymorphism where there are more than 40 repeats increases the risks of huntington’s.
X linked recessive definition and example
Recessive gene on X chromosome. Haemophilia A
X linked dominant definition and example
Dominant gene on X chromosome
Mitochondrial
I hire item via mitochondria
G banding of chromosomes
Alternating light and dark band patterns on each chromosome pair
3 components of DNA
Deoxyribose, nitrogen base, phosphate
Enzyme that releases Supercoiled DNA for replication
Topoisomerase
Enzyme that separates the two strands of DNA
Helicase
Direction of DNA polymerase bases
5’ to 3’
Enzyme that gets rid of DNA primers
Exonuclease
DNA ligament role
Links Okazaki fragments
How telomerase works and what it does
It adds repetition of DNA bases at the ends of chromosomes, to prevent the lost of coding DNA in replication
What are Point mutations
When a single base is changed. Can be a silent mutation, where amino acid produced is the same, but can also be missense or nonsense mutation where amino acids. E.g. sickle cell anaemia (missense) or premature stop codon (nonsense).
Large scale mutations
Inversions, deletions, duplications or translocations.
Differences between eukaryotic and prokaryotic transcription and translation
What are the 3 modifications made to post transcriptional RNA
Splicing: removal of introns
Polyadenylation: adding of adenyl (A) nucleotides to the 3 prime end,
caping: RNA caping on 5’ end by the addition of 7-methylguanosine (phosphate group)
3 steps of prokaryotic transcription
Initiation (with sigma factor and RNA polymerase binding)
Elongation
Termination
Change in AA in sickle cell anaemia and what this causes
GAG to GTG
Glutamate to valine
This causes additional intra and inter cellular interactions that cause aggregation of cells and the sickle shape
Structure of t RNA (part that binds the AA and loops
Mechanism that allows t-RNA to bind to more than 1 codon coding for the same AA. (e.g. GCC and GCA both code for guanine but only 1 tRNA for both
Wobble pairing
molecules involved in termination of translation
Stop codon of mRNA presented to A site. Release factor (RF1 or RF2) binds. Hydrolysis of protein from tRNA. Ribosome complex is disassembled. Requires IF3 and Ribosomal recycling factor and GTP hydrolysis
Restriction enzymes what they are and the different types of cuts they do
Can be Cohesive ends of blunt ends
What is cDNA and how it is obtained
c (complementary) DNA is a DNA copy of the mRNA of a cell, created using the enzyme reverse transcriptase
use of dideoxynucleotides in DNA sequencing
Dideoxynucleotides cannot bind to other nucleotides on their 3’ end because the OH present in normal deoxynucleotides is changed to an H. Hence, the lenght of the resulting copied polynucleotides can tell what the nucleotides are.
Examples of structural variations of genome
deletions, additions, inversions…
Hardy Weinberg Principle
That allele and genotype frequencies will remain the same cross generations if nothing big influences this.
Heritability
The proportion of a phenotype that is due to genotype
