Exámenes

Question 1

Which combination of isochors is called “genome desert” due to a low concentration of genes?

Answer 1

L1, L2 & H1

Question 2

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

Answer 2

c. Retrotransposon elements

Question 3

Which of these cloning vectors has the highest capacity?

a. Plasmidics
b. Cosmidics
c. BACs
d. YACs

Answer 3

d. YACs

Question 4

Which of the next dispersed DNA repeat sequences is majority in the genome?

a. LINE
b. SINE
c. LTR

Answer 4

a. LINE

Question 5

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

Answer 5

d. 3’ UTR with 770 bp long

Question 6

The size of the human genome is

Answer 6

3.000 Mb

Question 7

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

Answer 7

b. Do not contain exons or introns

Question 8

Which types of dispersed DNA covers more Mb of the genome?

Answer 8

LINE

Question 9

What is the average identify of genome sequence (% of identical nucleotides) between two unrelated humans?

Answer 9

99,9%

Question 10

How many SNPs are different (on average) between two persons?

Answer 10

4 million

Question 11

If two SNPs show linkage disequilibrium, but we know that they are very distant, what is a likely cause for this?

Answer 11

It is likely that we have overlooked a genetic structure in our population

Question 12

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

Answer 12

a. There are more different SNPs than SVs between two unrelated people

Question 13

The protein p300 is a type of:

Answer 13

Histone acetylase (HAT)

Question 14

DNAse I Hypersensitive sites (DHS) are:

Answer 14

Regions of DNA not associated with nucleosomes

Question 15

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

Answer 15

B. Cover almost 20% of the sequence in the genome

Question 16

An epigenetic mark that can distinguish promoters from enhancers is

Answer 16

H3K4me3

Question 17

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

Answer 17

c. Expressino of JPX initiates the activation of XIST

Question 18

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

Answer 18

d. XIST transcripts bind to PRC2 proteins

Question 19

The reestablishment of imprinting patters in each reproductive cycle takes place during

Answer 19

Gametogenesis

Question 20

How many different combinations of chromosomes can be generated in each gamete during meiosis?

Answer 20

2^23

Question 21

Which component of the eukaryotic homologous recombination pathway has the same role as RecA in E.coli?

Answer 21

Rad51

Question 22

The main mechanism for the expansion of short tandem repeats is:

Answer 22

Strand-slippage during replication

Question 23

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

Answer 23

a. The FMR1 gene is silenced by an epigenetic mechanism

Question 24

O6-methyl-guanine pairs with

Answer 24

T

Question 25

Which DNA polymerase acts during BER?

Answer 25

DNA pol beta

Question 26

What repair system is more active in mitochondria?

Answer 26

BER

Question 27

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

Answer 27

c. XPG endonuclease cuts at 3' of the damage

Question 28

What disease is caused by mutations in the NBS1 gene?

Answer 28

Nijmegen breakage syndrome

Question 29

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

Answer 29

c. During the rearrangement of Ig genes

Question 30

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

Answer 30

b. Transversions should be more frequent than transitions

Question 31

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

Answer 31

d. Synonymous mutations never affect the splicing pattern

Question 32

What is the order of frequency of mutation types?

Answer 32

Non-sense < Mis-sense < Framshifts < Synonymous

Question 33

p.Tyr681Ter means

Answer 33

A nonsense mutation at position 681

Question 34

The function of snRNP U1 splicing is:

Answer 34

To bind the 5' splice site

Question 35

In the spliceosome, SR proteins:

Answer 35

bind splicing enhancers

Question 36

# 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

Answer 36

d. U2 replaces BBP at the branch site

Question 37

A mutation that destroys an exonic splicing enhancer could result in

Answer 37

skipping of that exon

Question 38

Mutation in the gene coding for an RTK that forms homodimers will most likely result in

Answer 38

A dominant phenotype through a dominant-negative effect

Question 39

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

Answer 39

c. Three polycistronic RNA molecules are formed: one from each promoter

Question 40

What statistical significance (p-value_ is required to accept association between a SNP and a disease in GWAS?

Answer 40

<5e-08

Question 41

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

Answer 41

d. All options are true

Question 42

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

Answer 42

c. They are useful to explain the pathogenic role of variants identified in GWAS studies