Exámenes Flashcards
Which combination of isochors is called “genome desert” due to a low concentration of genes?
L1, L2 & H1
It is true to affirm that both LINEs and SINEs are:
a. Transposon elements
b. Non-interspersed nuclear elements
c. Retrotransposon elements
d. Long terminal repeat elements
c. Retrotransposon elements
Which of these cloning vectors has the highest capacity?
a. Plasmidics
b. Cosmidics
c. BACs
d. YACs
d. YACs
Which of the next dispersed DNA repeat sequences is majority in the genome?
a. LINE
b. SINE
c. LTR
a. LINE
Which kind of UTR sequences are the longest?
a. 5’ UTR with 330 bp long
b. 5’ UTR with 770 bp long
c. 3’ UTR with 300 bp long
d. 3’ UTR with 770 bp long
d. 3’ UTR with 770 bp long
The size of the human genome is
3.000 Mb
Which of the next affirmations related with non-processed pseudogenes is not true?
a. Do not have promoters
b. Do not contain exons or introns
c. They have premature stop codons
d. They are copies of a gene originated by duplication and posterior mutation
e. They are incorrect versions of genes
b. Do not contain exons or introns
Which types of dispersed DNA covers more Mb of the genome?
LINE
What is the average identify of genome sequence (% of identical nucleotides) between two unrelated humans?
99,9%
How many SNPs are different (on average) between two persons?
4 million
If two SNPs show linkage disequilibrium, but we know that they are very distant, what is a likely cause for this?
It is likely that we have overlooked a genetic structure in our population
Regarding SNPs and structural variants:
a. There are more different SNPs than SVs between two unrelated people
b. There are more different SVs than SNPs between two unrelated people
c. The total number of nucleotides comprised by SNPs in one person is greater than total number of nucleotides comprised by SVs
d. SNPs usually cause neurodevelopmental disorders
a. There are more different SNPs than SVs between two unrelated people
The protein p300 is a type of:
Histone acetylase (HAT)
DNAse I Hypersensitive sites (DHS) are:
Regions of DNA not associated with nucleosomes
DHS in the human genome:
a. Are usually present in many different cell types
b. Cover almost 20% of the sequence in the genome
c. Most of them are in exons
d. Most of them are in the promoters of protein-coding genes
B. Cover almost 20% of the sequence in the genome
An epigenetic mark that can distinguish promoters from enhancers is
H3K4me3
During the X chromosome inactivation:
a. JPX is active in both X chromosomes at the beginning of the process
b. The function of PRC2 is to revent XIST transcription
c. Expression of JPX initiates the activation of XIST
d. All options are true
c. Expressino of JPX initiates the activation of XIST
During the inactivation of the X chromosome
a. The gene JPX is transcribed as a protein-coding RNA
b. CTCF binds to TSIX at thhe initiation of inactivation
c. Inactivation is stabilized through the acetylation of H3K27
d. XIST transcripts bind to PRC2 proteins
d. XIST transcripts bind to PRC2 proteins
The reestablishment of imprinting patters in each reproductive cycle takes place during
Gametogenesis
How many different combinations of chromosomes can be generated in each gamete during meiosis?
2^23
Which component of the eukaryotic homologous recombination pathway has the same role as RecA in E.coli?
Rad51
The main mechanism for the expansion of short tandem repeats is:
Strand-slippage during replication
In Fragile X Syndrome:
a. The FMR1 gene is silenced by an epigenetic mechanism
b. There is an expansion of a CAG repeat in the promoter of the FXA gene
c. There is an expansion of a CGG reeat in the coding region of the FMR1 gene
d. Both X chromosomes must be mutated
a. The FMR1 gene is silenced by an epigenetic mechanism
O6-methyl-guanine pairs with
T
Which DNA polymerase acts during BER?
DNA pol beta
What repair system is more active in mitochondria?
BER
About NER:
a. XPB endonuclease cuts at 5’ of the damage
b. XPF endonuclease cuts at 3’ of the damage
c. XPG endonuclease cuts at 3’ of the damage
d. XPC endonuclease cuts at 3’ of the damage
c. XPG endonuclease cuts at 3’ of the damage
What disease is caused by mutations in the NBS1 gene?
Nijmegen breakage syndrome
DSBs are generated:
a. During anaphase meiosis II
b. Because of UV radiation
c. During the rearrangement of Ig genes
d. All of the options are correct
c. During the rearrangement of Ig genes
About transversions and transitions:
a. In fact, transversions are more frequent cause of disease than transitions
b. Transversions should be more frequent than transversions
c. In theory, there should be twice as many transitions as transversions
d. Transitions should be more frequent than transversions
b. Transversions should be more frequent than transitions
One of the following statements about point mutations in coding regions is wrong:
a. Nonsense mutations create a truncated protein which is usually non-functional
b. Mis-sense mutations never originate a stop codon
c. Synonymous mutations can affect the rate of protein translation
d. Synonymous mutations never affect the splicing pattern
d. Synonymous mutations never affect the splicing pattern
What is the order of frequency of mutation types?
Non-sense < Mis-sense < Framshifts < Synonymous
p.Tyr681Ter means
A nonsense mutation at position 681
The function of snRNP U1 splicing is:
To bind the 5’ splice site
In the spliceosome, SR proteins:
bind splicing enhancers
Choose the correct statement about the spliceosome:
a. The RNA-free proteins that participate in the process are: BBP, U2AF, U1, U2, U4, U5 and U6
b. In the first step, U2 auxiliary factor (U2AF) binds to the polypyrimidine track
c. U4 interacts with U2 from the active site
d. U2 replaces BBP at the branch site
d. U2 replaces BBP at the branch site
A mutation that destroys an exonic splicing enhancer could result in
skipping of that exon
Mutation in the gene coding for an RTK that forms homodimers will most likely result in
A dominant phenotype through a dominant-negative effect
During the transcription of mitochondrial DNA
a. The main DNA polymerase is DNA-gamma
b. 37 genes are transcribed from their promoters: 13 tRNAs, 22 mRNAs and 2 rRNAs
c. Three polycistronic RNA molecules are formed: one from each promoter
d. Two polycistronic RNA molecules are formed: one from the heavy chain and one from the light chain
c. Three polycistronic RNA molecules are formed: one from each promoter
What statistical significance (p-value_ is required to accept association between a SNP and a disease in GWAS?
<5e-08
In a GWAS study for a dichotomous (binary) trait
a. Association can be tested with logistic regression
b. The odds ratio can be estimated from the beta value
c. The odds ration can be measured directly
d. All options are true
d. All options are true
With regard to eQTLs
a. They have been identified by HapMap project
b. They are polymorphic microsatellites
c. They are useful to explain the pathogenic role of variants identified in GWAS studies
d. All options are correct
c. They are useful to explain the pathogenic role of variants identified in GWAS studies
