Integrated Exam 3 Review

The components of DNA include

A: A nitrogenous base

B: A 3' deoxyribose

C: A phosphate

D. A 2 deoxyribose

E: Histones

A: A nitrogenous base

C: A phosphate

D. A 2 deoxyribose

For the A-T base pair

A: A is the purine

B: A is the pyrimidine

C: It involves 3 hydrogen bonds.

D: They interact through phosphodiester bonds

E: It Is only found on DNA

A: A is the purine

E: It Is only found on DNA

3 For the following sequence: 5'-gaatttccc-3', the complementary sequence is:

A: 5'-ccctttaag-3'

B: 5 -gggaaattc-3'

C: 3'-gggaaattc-5'

D: 3'-ccctttaaag-5'

E: None of the above

B: 5 -gggaaattc-3'

Chromosome structure includes

A: A 5'-CAP

B: Telomeres

C: Multiple centromeres

D: Multiple origins of replication

E: Histones

B: Telomeres

D: Multiple origins of replication

E: Histones

Nucleosomes

A: Are composed of histones H2A, H2B, H3 and H4

B: Contain histone H1l

C: Look like beads on a string

D: Are positively charged

E: Are negatively charged

A: Are composed of histones H2A, H2B, H3 and H4

C: Look like beads on a string

D: Are positively charged

A karyotype

A: Is the sequence of the genes in the chromosomes

B: Is the number an appearance of chromosomes in the G1 phase of a coll

C: Is the number an appearance of metaphase chromosomes in the cell

D: Can be used to diagnose chromosomal abnormalities

E: Displays haploid (1n) content of the genome

C: Is the number an appearance of metaphase chromosomes in the cell

D: Can be used to diagnose chromosomal abnormalities

Which of these statements is correct

A: The flow of genetic information is only unidirectional

B: An allele is a variation of the sequence of a gene inherited by one of the parents

C: Eukaryotic chromosomes are circular

D: Replication initiates at the centromere

E: Nucleosomes impede gene transcription

B: An allele is a variation of the sequence of a gene inherited by one of the parents

E: Nucleosomes impede gene transcription

For DNA synthesis, DNA polymerase requires the following:

A: Dideoxynucleotides (ddNTPs)

B: A primer with an available 5' end

C: A primer with an available 3' end

D: A DNA template

E: NTPS

C: A primer with an available 3' end

D: A DNA template

The correct sequence of cell cycle phases is:

A: GO, G1, G2, S and M

B: GO, G1, G2, S, and M

C: GO, G1, M, G2 and S

D: GO, G1, S, G2 and M

E: M, S, GO, G1 and G2

D: GO, G1, S, G2 and M

The supercoils generated on DNA by the movement of the replicated fork is relieved by

A: DNA helicases

B: Single-stranded DNA binding proteins

C: Topoisomerases

D: Primases

E: DNA ligase

C: Topoisomerases

You expect that most primase molecules would be associated to

A: The promoter of an actively transcribed gene

B: The lagging strand in DNA replication

C: DNA Mismatch

D: The leading strand in DNA replication

E: Recombination complexes

B: The lagging strand in DNA replication

The proofreading activity of replicative DNA polymerases

A: Proceeds in the 3' to 5' direction

B: Proceeds in the 5' to 3' direction

C: Generates a 3' end

D: Generates a 5' end

E: Requires DNA Mismatch Repair

A: Proceeds in the 3' to 5' direction

Okazaki fragments

A: Occur in the lagging strand

B: Occur in the leading strand

C: Are synthesized in the 3' to 5' direction

D: Contain a DNA primer

E: Require the activity of RNAse H for processing

A: Occur in the lagging strand

E: Require the activity of RNAse H for processing

Telomeres

A: Are sequences in origins of replication

B: Are replicated using an RNA template

C: Contain 3' overhangs

D: Contain 5' overhangs

E: Are present at the end of chromosomes

B: Are replicated using an RNA template

C: Contain 3' overhangs

E: Are present at the end of chromosomes

Retroviruses

A: Require DNA polymerase for replication of the viral genome

B: Are DNA viruses which are converted into RNA before they are replicated

C: Are RNA viruses which are converted into DNA before integrating into the genome

D: Require Reverse Transcriptase to make multiple copies of the viral genome

E: Requires RNA polymerase to make multiple copies of the viral genome

C: Are RNA viruses which are converted into DNA before integrating into the genome

E: Requires RNA polymerase to make multiple copies of the viral genome

When RNA polymerase transcribes a gene

A: It uses the coding strand (sense) as the template

B: It uses the antisense as the template

C: It incorporates NTPs in the 5' to 3' direction

D: It incorporates NTPs in the 3' to 5' direction

E: It requires a primer

B: It uses the antisense as the template

C: It incorporates NTPs in the 5' to 3' direction

Which of these elements are part of promoters

A: TATA box

B: Enhancer

C: Splicing site

D: Polyadenylation sequences

E: 3' untranslated region

A: TATA box

B: Enhancer

The first step of transcription involves

A: The binding of the RNA polymerase to the promoter

B: The binding of FIlA to the enhancer

C: The binding of the TATA-binding protein (TBP)

D: The synthesis of an RNA primer by Primase

E: The addition of a 5'-CAP

C: The binding of the TATA-binding protein (TBP)

An Operon

A: Is transcribed into a polycistronic mRNA

B: Is commonly found in eukaryotic cells

C: Contains multiple promoters

D: Encodes a single large gene

E: None of the above

A: Is transcribed into a polycistronic mRNA

The 5' UTR or leading sequence of mRNA contains

A: Coding sequence

B: Non-coding sequence

C: Ribosomal binding site

D. Promoter sequences

E: Polyadenylation signal

B: Non-coding sequence

C: Ribosomal binding site

The 5'-CAP

A: Is required for stability of the mRNA

B: Is required for ribosome binding

C: Is added to the mRNA by the RNA polymerase

D: It is attached to the 3'-OH of the first nucleotide of the mRNA

E: None of the above

A: Is required for stability of the mRNA

B: Is required for ribosome binding

Polyadenylation

A: Is carried out by RNA polymerase II

B: Requires a template

C: Is normally the addition of around 250 adenine nucleotides

D: Is required to prevent mRNA degradation

E: Occurs at specific restriction sites.

C: Is normally the addition of around 250 adenine nucleotides

D: Is required to prevent mRNA degradation

In RNA splicing

A: Introns are removed

B: Exons are removed

C: The 5'-splice site and 3'-splice site in the primary transcript are required

D: Exons form a lariat

E: Is carried out by snRNPs

A: Introns are removed

C: The 5'-splice site and 3'-splice site in the primary transcript are required

E: Is carried out by snRNPs

In translation

A: Each amino acid is encoded by a unique codon

B: The tRNA anticodon binds to an identical sequence in the mRNA

C: The mRNA can be read in three different frames

D: A frameshift mutation does not result in changes in the protein sequence

E: The first amino acid is a methionine in eukaryotes

C: The mRNA can be read in three different frames

E: The first amino acid is a methionine in eukaryotes

During initiation of protein synthesis

A: Both of the subunits of the ribosome assembles first, followed by mRNA binding

B: The tRNA for the first amino acid binds to the P site of the ribosome

C: Requires eEF1A

D: The first codon is scanned beginning from the cap

E: The tRNA for the first amino acid binds to the A site

B: The tRNA for the first amino acid binds to the P site of the ribosome

D: The first codon is scanned beginning from the cap

In general, excision type DNA repair pathways involve

A: The action of endonucleases

B: DNA damage recognition proteins

C: DNA polymerases

D: Strand exchange

E: Resolution of Holliday junctions

A: The action of endonucleases

B: DNA damage recognition proteins

C: DNA polymerases

Chromosomal translocations

A: Are a consequence of abnormal homologous recombination

B: Occur on homologous chromosomes

C: Involve strand exchange

D: Can lead to diseases.

E: Is a normal DNA repair mechanism

A: Are a consequence of abnormal homologous recombination

C: Involve strand exchange

D: Can lead to diseases.

In gene expression control of operons, the repressor

A: Can be regulated by an inducer

B: Binds to an operator sequence

C: Blocks binding of the RNA polymerase to the promoter

D: Is encoded by a gene in the operon

E: Can be in inactive form

A: Can be regulated by an inducer

B: Binds to an operator sequence

C: Blocks binding of the RNA polymerase to the promoter

E: Can be in inactive form

Epigenetic regulation of gene expression includes

A: Modification of histones

B: Genetic polymorphisms

C. Gene amplification

D: Regulation of the mRNA stability

E: Microdeletions in chromosomes

A: Modification of histones

Methylation of DNA at CpG islands

A: Results in increased transcription of the gene

B: Allows chromatin remodeling

C: Reduces transcription of the gene

D: Is associated with developmental syndromes (e.g. Prader-Will Syndrome)

E: Has no effect on gene expression

C: Reduces transcription of the gene

D: Is associated with developmental syndromes (e.g. Prader-Will Syndrome)

The steroid hormone receptor

A: interacts directly with the polymerase

B: Binds to the hormone response element (HRE)

C: Stimulate transcription

D: Has a hormone binding domain

E: Is always located in the nucleus

B: Binds to the hormone response element (HRE)

C: Stimulate transcription

D: Has a hormone binding domain

For cells to become cancerous. the following events should occur

A: Activation of tumor suppressors

B: Activation of proto-oncogenes

C: Lost of cell cycle checkpoints

D: Accumulation of mutations

E: None of the above

B: Activation of proto-oncogenes

C: Lost of cell cycle checkpoints

D: Accumulation of mutations

The two-hit hypothesis for carcinogenesis proposes that

A: Both alleles of an oncogene need to be inactivated

B: Both alleles of a tumor suppressor gene need to be inactivated

C: One allele of a tumor suppressor and one allele of an oncogene need to be inactivated

D: One allele of a tumor supprassor gene needs to be inactivated and one allele of an oncogene needs to be activated

E: One allele of a tumor suppressor gene needs 2 mutations to be inactivated

B: Both alleles of a tumor suppressor gene need to be inactivated

Cyclin-dependent kinases control the cell cycle by

A: Phosphorylating Cyclin D

B: Phosphorylating E2F

C: Phosphorylating Rb

D: Associating with a cyclin

E: Phosphorylating p53

C: Phosphorylating Rb

D: Associating with a cyclin

The role of Rb in the G1 to S cell cycle transition is

A: To activate the cdk-cyclin complex

8: To activate p53.

C: To increase gene transcription

D: To sequester E2F in the cytoplasm

E: To induce apoptosis

D: To sequester E2F in the cytoplasm

The role of p53 in the prevention of carcinogenesis is to

A: Activate DNA repair upon DNA damage

B: Arrest calls to prevent replication of damaged DNA

C: Bind E2F and block its activity

D: Degrade the cdk-cyclin complex

E: Block Ras activity

A: Activate DNA repair upon DNA damage

B: Arrest calls to prevent replication of damaged DNA

The most common cancer in women is

A: Ovarian

B: Breast

C: Uterus

D: Lung

E: Colon

B: Breast

The sequence most likely to be a restriction site is

A: 5-GCCCCG-3'

B: 5'-TATTAT-3'

C: 5'-GGATCC-3'

D: 5'-AAAAAA-3'

E: 5'-CCTTCC-3'

C: 5'-GGATCC-3'

Plasmids

A: Occur naturally In bacteria

B: Do not need an origin of replication

C: May confer drug resistance to the bacterium

D: Are useful genetic tools

E: Are bacterial viruses

A: Occur naturally In bacteria

C: May confer drug resistance to the bacterium

D: Are useful genetic tools

Sequencing by the chain termination method (Sanger method)

A: Requires a DNA template

B: Requires ligase

C: Requires a DNA polymerase

D: Requires dideoxynucleotides

E: Requires Primase

A: Requires a DNA template

C: Requires a DNA polymerase

D: Requires dideoxynucleotides

Regarding DNA gel electrophoresis

A: DNA migrates to the negative electrode

B: DNA migrates to the positive electrode

C: Larger DNA fragments migrate faster than small ones

D: Larger DNA fragments migrate slower than small ones

E: Is used in FISH analysis

B: DNA migrates to the positive electrode

D: Larger DNA fragments migrate slower than small ones

Cloning genes into plasmids

A: Can be used to express proteins for therapeutic purposes

B: Can be monitored by checking blue/white color colonies

C: Uses restriction enzymes to cut DNA

D: Requires selection with an antibiotic

E. All of the above

E. All of the above

The Holliday Model describes

A: The repair of mismatches

B: Base Excision Repair

C: Nucleotide Excision Repair

D: Homologous Recombination

E: The repair of Okazaki fragments

D: Homologous Recombination

T/F: Acetylation is a post-transcriptional modification of RNA

False

A zinc finger motif is most likely found in

A. DNA topoismerases

B. DNA helicases

C. Histones

D. Transcription factors

E. U2SnRNP

D. Transcription factors

The open reading frame (ORF)

A. Includes the 5-UTR

B. Includes the 3-UTR

C. Includes introns

D. Starts at the +1 nucleotide

E. Ends at the stop codon

E. Ends at the stop codon

T/F: The aminoacid is attached to the anticodon of the tRNA

False

T/F: The lariat forms during the splicing reaction

True

A microRNA (miRNA)

A. regulates the levels of mRNAs

B. Is used in the splicing reaction to identify the 5’- splice site

C.

D.

E.