Final Flashcards
Which sampling method will provide earlier analysis of foetal DNA:
Chorionic Villus Sampling
or
Amniocentesis?
Chorionic Villus Sampling
In the autosomal recessive disease Galactosaemia, mutations in which gene will cause cataracts?
- GALT*
- GALK1*
- GALE*
GALK1
Ankylysing Spondylosis is a result of mutations in what gene?
(Gene and Locus)
MHC Class I - Locus B27
Which Cyclin Dependant Kinase inactivates the ORC (Origin Recognition Complex)?
S-Cdk
Chromosomes of what morphology may be subject to Robertsonian Translocation?
Acrocentric
Traits occuring in only one sex due to anatomical differences are classified as:
Sex-limited Traits,
or
Sex-Influenced Traits?
Sex-Limited Traits
Where is the site of original de-novo mutation in Germline Mosaicism?
The embryo
Ineffective platelets, eczema and T-Cell abnormalities leading to susceptibility to opportunistic infections are a feature of which X-Linked Recessive disease?
Wiskott-Aldrich Syndrome
In the autosomal recessive disease Galactosaemia, mutations in which gene will cause the most common and severe form?
- GALT*
- GALK1*
- GALE*
GALT
The autosomal Dominant disorders Holoprosencephaly and Grieg Cephalopolysyndactyly Syndrome, are caused by mutation of which protein signalling pathway?
(sonic) Hedgehog Signalling Pathway
Behaviour of Enhancer and Silencer regions of DNA during transcription are regulated by:
What type of cell the DNA is located in
A nucleocapsid consists of what two materials?
Capsid Protein
Genetic material (DNA or RNA)
Genetic conditions such as Marfan’s Syndrome with a spectrum of mild to severe features is conisdered to have:
Variable Expressivity
In autosomal recessive Chronic Granulomatous Disease, which enzyme, critical for phagocytosis is missing?
NADPH oxidase
What process is required to trigger the degradation of M-Cyclin after mitosis?
Ubiquitination
What immunodeficient disease is charachterised by deficient MHC class II expression?
Type II BLS
Bare Lymphocyte Syndrome
Ribosomal subunits of 40S and 60S are associated with prokaryotes or eukaryotes?
Eukaryotes
Thanatophoric Dysplasia, a severe skeletal malformation disease, is caused by mutation of which particular growth factor gene?
FGFR3
Bacteria which have mutated to resist antibiotic drugs will eventually become the majority of the population of that particular bacteria - is this horizontal or vertical resistance gene transfer?
Vertical
Swyer Syndrome results from an error in the SRY / SOX9 crossover process, does this result in an XX Male, or an XY Female?
XY Female
Also Known as XY Gonadal Dysgenesis
in MILS (Maternally-inherited Leigh Syndrome) what is encoded by the affected gene, MT-ATP6?
ATP synthase
What is the typical recurrence risk for an Autosomal Recessive disease?
25%
What are the three steps of a PCR (Polymerase Chain Reaction) analysis?
Denaturation
Annealing
Extension
What are the three forms of Tay-Sachs disease?
Infantile
Juvenile
Adult/Late
Does genetic testing reveal mutations, or the presence of disease?
Mutations
What are the molecules which toggle DNA replication and cell division activities?
Cyclins
Which of the following paracrine signalling molecules plays a role in axial development:
- WNT* (wingless genes)
- or*
Fibroblast Growth Factor
WNT
The enzyme Activation Induced Deaminase is important for what process?
Somatic Hypermutation
Double stranded DNA is the mechanism of gene therapy in:
Adeno-Associated Vector
or
Adenovirus Vector?
Adenovirus vectors
RNA is probed by Northern or Southern blotting?
Northern
Erythroblastosis Fetalis is a hemolytic disease resulting in spontaneous abortion of the fetus - what gene is responsible?
RH blood gene
Non-ionising radiation may have the following effect on DNA:
Single or double stranded breaks in DNA backbones
or
Binding of adjacent Thymine bases to one another
Binding of adjacent Thymine bases to one another
DNA Polymorphisms such as SNPs or STRs can be used as markers in what type of diagnostic tests?
Linkage Analysis
S-Cdk causes the inactivation of ORC by destruction of Cdc6, why?
To prevent re-replication
<em>(DNA is replicated ONCE during the cell cycle)</em>
What type of newborn screening test is used to detect protein variants that signal amino acid disorders?
Tandem Mass Spectrometry
The two structures of viral genomes, Circular and Linear, are both further broken down in what two classifications?
Segmented
Non-Segmented
In the Hardy-Weinberg Law formula: p2 + 2pq + q2 = 1 , what does the 2pq represent in terms of alleles?
Frequency of the Aa combination
In a dominant gene disease, which allele is pathogenic, d or D?
D
Cri-du-chat Syndrome is a resut of a deletion or a translocation of chromosome 5?
Deleted
Which of the following virii are able to be used directly as mRNA for protein synthesis?
ssRNA (+)
ssRNA (-)
ssRNA (+)
Are proteins encoded by rRNA?
no
What enzyme joins Okazaki fragments along the lagging strand together to form a complete strand (parallel to the parent?)
DNA Ligase
What is the name of the deactivated X chromosomes in the cells of women?
Barr bodies
By what mechanism does Cytomegalovirus avoid detection by cytotoxic T-Cells?
Downregulation of MHC class 1 Genes
Hirschprung disease is a common feature of birth defects such as Trisomy 21 and Waardenburg Syndrome - what causes Hirschprung Disease?
Lack of developement of the Enteric Nervous System
A male inheriting an X-Linked dominant disease would have gained the allele from the mother or the father?
Mother
What is the medical term for a factor which has caused a mutation to take place?
Mutagen
The Complement molecules of the immune system are coded by which class of Major Histocompatibility Complex?
Class III
In X-Linked Recessive diseases, why is maternal transmission of disease always expressed in sons?
Males do not have a compensatory allele for the affected X-Chromosome gene
What is the medical tem for tumours of the epithelial tissues?
Carcinoma
Ribosomal subunits of 50S and 30S are associated with prokaryotes, or eukaryotes?
Prokaryotes
Hereditary non-polyposis colon cancer is also known as:
Leisch Nyhan syndrome
DNA is read in the 3’ ⇒ 5’ direction, hence DNA is synthesised in the:
5’ ⇒ 3’ direction
The Prader-Willi gene on chromosome 15 is active, or inactive in maternal chromosomes?
Inactive
What is the phenomenon that describes defective genes in different chromosomes causing the same disease?
Locus Heterogeneity
Curly wooly hair and a webbed neck are features of Noonan Syndrome - this is caused by mutation of what gene?
RAS-MAKP
An effective screening test is desirably of a high:
Sensitivity
or
Specificity
Sensitivity
The probability of a child having a genetically inherited disease is proportional to the number of siblings they have.
True
or
False?
False.
Two non-homologous acrocentric chromosomes loose their short arms (P), and the residual long arms (Q) fuse to form one long chromosome - what is this phenomenon refererred to as?
Robertsonian Translocation
Sensitivity is given as a function of true positives, divided by:
True positives + False Negatives
25% of cases of Prader-Willi syndrome are caused by uniparental disomy of chromosome 15 - what does this mean?
The child inherits both copies of Chromosome 15 from the same parent
(Maternal in this case)
HOX genes clusters consist of normal genes, and what?
Pseudogenes
Supravalvular Aortic Stenosis results from mutations in which of the following gene products?
- Fibrillin-1*
- Elastin*
Elastin
What is the medical term for an abnormal number of chromosomes within a cell?
Aneuploidy
What is Pleitropy?
single genes having more than one discernible effect on the body
What will be the Theta value of two completely linked genes?
0
What is the purpose of maintenance methylation?
methylating newly synthesised strands of DNA
Gene therapy with antisense oligonucleotides corrects for what type of mutations?
Gain of function mutations
Proteins are the subject of:
Southern Blotting
Western Blotting
Northern Blotting?
Western Blotting
Sickle Cell disease
Tay-Sachs disease
Cystic Fibrosis
Phenylketonuria
These disease are detected by what type of screening?
Heterozygote screening
IRT (Immunoreactive Trypsinogen) is the subject of a diagnostic test for what disease?
Cystic Fibrosis
A needle passed through the abdomen to collect samples for analysis
describes:
Chorionic Villus Sampling
or
Amniocentesis
Amniocentesis
The carbon ring in a nucleotide contains 4 or 5 Carbons?
4 Carbons
When calculating the frequency of alleles, the number (n) of homozygous (AA) or heterozygous (Aa) samples must be doubled before dividing by 2N?
Homozygous (AA)
What is the most straightforward method of epigenetic control?
DNA Methylation
During conjucation by bacteria, genetic material travelling through the sex pilus originates from the:
Bacterial Chromosome
or
a Plasmid?
Plasmid
The subunit formed by DNA wrapped around eight histones is known as a:
Nucleosome
If some people with a mutation of a gene do not develop the features of the disorder, the condition is said to have:
A reduced penetrance
What is the typical recurrence risk of an autosomal recessive disease?
25%
During methylation, which enzyme adds the first methyl group?
de novo methylase
or
Maintenance methylase
de novo methylase
Rostrocaudal symmetry of axial development is regulated by proteins expressed by what genes?
Sonic the Hedgehog Genes
SHH
Myotonic Dystrophy is an autosomal dominant, or recessive disease?
Autosomal Dominant
Continuation of the leading strand of DNA is done by which Polymerase?
DNA Polymerase Epsilon
Exonucleases perform what function?
Error checking and correction
What component of the Helicase (MCM) is destroyed by S-Cdk?
Cdc6
Resistance gene transfer that is achieved by absorption of new DNA from the external environment is an example of:
- Conjugation*
- Transduction*
- Transformation*?
Transformation
In mitochondrial replacement therapy, in which method is repair carried out before fertilisation?
Pronuclear Transfer
Maternal Spindle Transfer
Maternal Spindle Transfer
A section of DNA incorporated in to the bacterial chromosome by a virus is known as a:
Prophage
In what disease are the phagocytes able to take in bacteria and fingi, but unable to kill them?
CGD
Chronic Granulomatous Disease
Inherited Brachydactyly (short digits) results from what type of mutation of CDMP 1 genes?
Misense
or
Nonsense
Nonsense
Transduction of non-dividing cells in gene therapy requires what vector?
Adeno-associated virus
Which feature of a DNA strand encodes proteins?
Exons
or
Introns?
Exons
Which genetic disease is linked to eating fava beans and some oxidative drugs?
G6PD deficiency
What is the diploid number for human somatic cells?
23
PPV (Positive predictive value) measures the ability to:
Detect the presence of a disease
or
Detect the absence of a disease
Detect the presence of a disease
Mutation in which BMP family gene causes fusion of the bones in various joints?
Noggin
The person about who’s future offspring the genetic analysis refers, is known as:
The consultand
What is the purpose of Alternative Splicing in protein synthesis?
Allowing for multiple RNA/Proteins to be produced from the same set of exons.
What are the two forms of Huntington’s Disease?
Adult Onset
Juvenile Onset
What are Lymphomas?
Tumours of the lymphatic tissues
What is the inheritance risk of retinoblastoma if one parent is affected?
50%
With relation to chromosome 15, by what three mechanisms will a patient develop either Prader-Willi Syndrome or Angelman Syndrome?
Uniparental disomy
Defective imprinting
Deletion
Adenine and Guanine are:
Purines
or
Pyramidines?
Purines
A law states* that genotype and allele frequencies will always remain constant from generation to generation - what is this law?
*provided certain criteria are met
Hardy-Weinberg Law
What disease is also known as Bubble Boy disease?
SCID
What is a Sarcoma?
Tumours of connective tissues
What sequences upstream from the gene promoter site function to regulate DNA transcription to RNA?
Enhancers and Silencers
Is Male Pattern Baldness a Sex-Limited trait, or a Sex-Influenced trait?
Sex-Influenced Trait
Mutations in CYP21A2 are associated with which disease?
Congenital Adrenal Hyperplasia
What are the three types of horizontal resistance gene transfer in bacteria?
Transformation
Conjugation
Transduction
Genetic material, combined with Capsid Protein is known as a:
Nucleocapsid
Using the Knudson Hypothesis, explain the earlier onset of Retinoblastoma in a child with an affected parent?
The inerited mutation has provided the ‘first hit’ already
What are the two morphological structures of viral genomes?
Linear
Circular
Reducing the distance between loci of syntetic genes will increase or decrease the recombination frequency?
Decrease
Pairs of sister chromatids are joined by a special DNA sequence known as a:
Centromere
What does Haplosufficient mean?
Accounting for any mutation, there are sufficient proteins produced to maintain homeostatic function
The Angelman Syndrome gene on chromosome 15 is active, or inactive in maternal chromosomes?
Active
Father to son transmission of genetic disease is an attribute of Autosomal Dominant, or Autosomal Recessive?
Autosomal Dominant
According to the two-hit (Knudson) theory, in order for a cell to initiate a tumour it must have:
Two damaged alleles
Specificity of a medical test measures the ability to correctly identify:
True Positives
or
False Negatives
False Negatives
Is mitochondrial inheritance maternal, or paternal?
Maternal
What are the three classes of prenatal diagnosis of genetic disorders?
Invasive Diagnostic Testing
Foetal Visualisation Techniques
Population Screening