Deck 17: Nucleic Acids

Question 1

Which of the following is/are differences between DNA and RNA

A) DNA is single stranded
B) RNA is double stranded
C) RNA contains uracil
D) RNA is single stranded
E) Both D and E are correct

Answer 1

E

Question 2

Which of the following describes the flow of genetic information as stated in the central dogma of molecular biology?

A) RNA  Protein  DNA
B) DNA  RNA  Protein
C) DNA  Protein  RNA
D) Protein  RNA  DNA
E) None of the above is correct

Answer 2

B

Question 3

The DNA "backbone" is composed of

A) An amide bond between deoxyribose and a nitrogenous base
B) A glycosidic bond between deoxyribose and a nitrogenous base
C) A phosphodiester bond between 3^! and 5^! hydroxyl groups of adjacent deoxyribose residues
D) A phosphodiester bond between 2^! and 5^! hydroxyl groups of adjacent deoxyribose residues
E) None of the above is correct

Answer 3

C

Question 4

Nucleosomes are composed of all of the following except ________.

A) H1
B) H2
C) H3
D) H4
E) H5

Question 5

There are approximately _________ human genes.

A) 10,000
B) 20,000
C) 100,000
D) 1,000,000
E) 10.000.000

Question 6

______ are gene sequences that code for a gene product.

A) Introns
B) Exons
C) Nucleosomes
D) Cruciforms
E) Snurps

Question 7

A genome is

A) The sequence that contains the base sequence information necessary to code for a gene product
B) The complete DNA base sequence in an organism
C) The complementary pairing of purine and pyrimidine bases
D) A base pair
E) A newly synthesized RNA molecule

Question 8

Protein synthesis is called

A) Translation
B) Transcription
C) Replication
D) A metabolome
E) Proteome

Question 9

The entire set of proteins synthesized by a cell is called

A) Metabolome
B) Genome
C) Proteome
D) Epigenome
E) Transcriptome

Question 10

The polyamines assist in the compression of eukaryotic chromosome structure because they

A) Contain functional groups that bond to DNA
B) Assist in the formation of telomeres
C) Possess positive charges that interact with the negative charges of DNA
D) Promote chemical modification of the histones
E) None of the above is correct

Question 11

In nucleosome structure the histone ________ aids in stabilizing the wrapping of DNA around the protein octomer.

A) H1
B) H2A
C) H2B
D) H3
E) H4

Question 12

Chromatin contains several levels of structure which include

A) Nucleosomes
B) 200 nm filaments
C) 30 nm fiber
D) Both B and C are correct
E) All of the above are correct

Question 13

D loops and variable loops are found in _______

A) Mrna
B) rRNA
C) tRNA
D) hnRNA
E) snRNA

Question 14

Which of the following are involved in the splicing of RNA molecules?

A) Snurps
B) snRNA
C) rRNA
D) Both A and B are correct
E) None of the above is correct

Question 15

The DNA strand that acts as a template during transcription is referred to as the ______ strand.

A) Sense
B) Antisense
C) Transcribed
D) All of the above are correct
E) None of the above is correct

Question 16

Determine the mRNA sequence for the following DNA sequence.
5'-GCCATTTCCCGTTA-3'

A) 5'-CGGTAAAGGGCAAT-3'
B) 5'-CGGUAAAGGGCAAU-3'
C) 5'-TAACGGCAAATGGC-3'
D) 5'-UAACGGCAAAUGGC-3'
E) 5'-UAACGGGAAAUGGC-3'

Question 17

Which of the following does not contribute to the noncovalent interactions that stabilize the helical strands of DNA

A) Hydrophobic interactions
B) Phosphodiester bonds
C) Hydrogen bonds
D) Base stacking
E) Hydration

Question 18

During a transition mutation which of the following bases would be substituted for cytosine?

A) Thymine
B) Adenine
C) Guanine
D) Both B and C are correct
E) All of the above are true

Question 19

The polyamines are a class of DNA binding molecules that include ______.

A) Spermine
B) Speruline
C) Spermidine
D) Both A and C are correct
E) All of the above are correct

Question 20

_______ are structures that occur at the ends of chromosomes

A) Cistrons
B) Telomeres
C) Cruciforms
D) Centromeres
E) Capsids

Question 21

HIV infection of a susceptible cell is initiated when the gp120 envelope protein binds the _______ antigen.

A) T4
B) C4
C) T2
D) C2
E) None of the above is correct

Question 22

HIV is a type of

A) Pox virus
B) Rhabdovirus
C) Herpes virus
D) Papilloma virus
E) Retrovirus

Question 23

HIV possesses a ________ genome

A) ssDNA
B) dsDNA
C) ssRNA
D) dsRNA
E) None of the above is correct

Question 24

Hydroxyapatite

A) Is a calcium phosphate gel
B) Binds to double stranded DNA
C) Is used in column chromatography
D) Both A and C are correct
E) All of the above are correct

Question 25

Southern blotting

A) Is a technique used to identify specific genes
B) Utilizes restriction enzymes
C) Is a chain terminating method
D) Both A and B are correct
E) All of the above are correct

Question 26

The genetic variations observed in DNA fingerprinting are referred to as ______.

A) RFLPs
B) RLFPs
C) FRLPs
D) DFLPs
E) DLFPs

Question 27

The extraction and purification of bacterial DNA involves the use of which of the following.

A) RNase
B) Lysozyme
C) Phenol and chloroform
D) Both A and B are correct
E) All of the above are correct

Question 28

Palindromes

A) Form cruciforms
B) Contain inverted repeats
C) Are sequences that provide the same information whether they are read forward or backwards
D) Play a role in the function of restriction enzymes
E) All of the above are correct

Question 29

The denaturation of DNA is

A) Promoted by heat, low salt concentration, and extremes of pH
B) Reversible
C) Monitored by measuring the absorbance at 300 nm
D) Both A and B are correct
E) All of the above are correct

Question 30

The chain terminating method for sequencing DNA was developed by

A) Maxam and Gilbert
B) Frederick Sanger
C) Watson and Crick
D) Hershey and Chase
E) None of the above is correct

Question 31

In a transversion mutation

A) A purine base is substituted for a pyrimidine base
B) A pyrimidine base is substituted for a purine base
C) A purine or pyrimidine base is frame shifted
D) Both A and B are correct
E) All of the above are correct

Question 32

A nucleoid is:

A) Supercoiled DNA attached to a protein core
B) Negatively supercoiled DNA
C) Positively supercoiled DNA
D) Relaxed DNA
E) Either B or C depending on the organism

Question 33

Chromatin is:

A) Supercoiled DNA
B) DNA complexed with histones
C) Linear uncoiled DNA
D) Relaxed DNA
E) Genes

Question 34

Intergenic sequences are

A) DNA segments that do not code for gene product
B) Junk DNA
C) DNA that codes for more than one product
D) DNA which stabilizes the nucleosome
E) Both A and B are correct

Question 35

Restriction enzymes

A) Prevent DNA synthesis
B) Prevent RNA synthesis
C) Prevent protein synthesis
D) Cut DNA at specific base sequences
E) Both A and B are correct

Question 36

The hypochromic effect is

A) The aggregation of chromatin into large clusters
B) The shift of light absorption to longer wavelengths
C) The formation of chromatin-histone complexes
D) The conversion of B-DNA to Z-DNA
E) The shift of light to shorter wavelengths

Question 37

Which of the following is the largest and most complex structure?

A) Genes
B) Nucleotides
C) Nucleosomes
D) Chromosomes
E) Chromatin

Question 38

Which of the following is not a function of RNA?

A) Regulation of gene expression
B) Cell differentiation
C) Catalysis
D) Both A and C are functions of RNA
E) All of the above are functions of RNA

Question 39

Which of the following statements is not true of mRNA?

A) Prokaryotic mRNAs are mainly polycistronic
B) Eukaryotic mRNAs are mainly monocistronic
C) Eukaryotic mRNAs are extensively modified after synthesis
D) Prokaryotic mRNAs are immediately transmitted into protein without covalent modifications
E) Prokaryotic mRNAs are capped with 7-methylguanosine

Question 40

Lysogeny is:

A) Cleavage of the cellular RNA
B) Infection of the host cell by a virus
C) Integration of the virus genome into the host chromosome
D) Formation of the prophage from the virus coat
E) None of the above is correct

Question 41

A defect in which of the following HAR's can result in microcephaly?

A) ASPM
B) FOXP2
C) AMY1
D) LCT
E) HAR1

Question 42

The change of a single base pair in a DNA chain is referred to as:

A) Transversion mutation
B) Silent mutation
C) Missense mutation
D) Point mutation
E) Nonsense mutation

Question 43

A mutation caused by an alkylating agent is referred to as

A) Transversion mutation
B) Silent mutation
C) Missing mutation
D) Point mutation
E) Nonsense mutation

Question 44

A point mutation that converts the code for an amino acid to a premature stop signal is referred to as

A) Transversion mutation
B) Silent mutation
C) Missing mutation
D) Point mutation
E) Nonsense mutation

Question 45

Which of the following is not an endogenous cause of DNA damage?

A) Tautomeric shift
B) Radiation
C) Deamination
D) Depurination
E) ROS induced oxidation

Question 46

Point mutations that occur in a population to any extent are referred to as

A) Silent mutations
B) Nonsense mutation
C) Transition mutation
D) Single nucleotide polymorphisms
E) Missense mutation

Question 47

What is molecular biology?

Question 48

What is the metabolome?

Question 49

What is a transversion mutation?

Question 50

What is a point mutation?

Question 51

What is a silent mutation?

Question 52

What are Chargaff's rules?

Question 53

List three biological properties facilitated by supercoiling.

Question 54

What are the three most prominent forms of RNA? What roles do they play in cell function?

Question 55

What features of the Z-DNA molecule allow the distinctive Zig Zag conformation to form?

Question 56

The melting point of a DNA molecule increases as the GC content increases. Explain.

Question 57

Provide the complementary strand and the RNA transcription product for the following DNA template segment: 5'- AGGGGCCGTTATCGTT-3'

Question 58

Describe the structural features that stabilize RNA molecules.

Question 59

Describe how DNA cell methylation patterns are retained from one cell generation to the next.

Question 60

What error would cause more damage to a cell: A DNA replication error or a DNA transcription error.

Question 61

When an aromatic hydrocarbon intercalates between two stacked base pairs, what effect may there be on DNA structure?

Question 62

Chargaff's rules apply to DNA but not RNA. Explain.

Question 63

Describe how water affects DNA structure.

Question 64

Under physiological conditions DNA ordinarily forms B-DNA, However, RNA hairpins and DNA-RNA hybrids adopt the structure of A-DNA. Considering the structural differences between DNA and RNA explain this phenomena.

Question 65

Jerome Vinograd found that when circular DNA from a polyoma virus is subjected to cesium chloride gradient centrifugation, it separates into two distinct bands, one consisting of supercoiled DNA and the other of relaxed DNA. Explain how you would identify each band.

Question 66

5-Bromouracil is an analogue of thymine which usually pairs with adenine. However, 5-bromouracil frequently pairs with guanine. Explain.

Question 67

The flow of genetic information is from DNA to RNA to protein. In certain viruses, the flow of information is from RNA to DNA. Is it possible for genetic information flow to begin with proteins? Explain.

Question 68

Your research requires the isolation of mitochondrial DNA without contamination with nuclear DNA. Describe how you would accomplish this task.

Question 69

The set of mRNA's present within a cell changes over time. Explain.

Question 70

Some organisms are under considerable strain to streamline their genomes for the sake of more efficient operation. As a result, the mitochondria of eukaryotic species have lost the overwhelming majority of their genes, of which several hundred were transferred to the nuclear genome. Yet mitochondria still retain a genome with the capacity to produce several electron transport proteins. Suggest a reason why these energy-generating organelles retained the genes to produce this set of molecules.

Question 71

The suggestion has been made that DNA extracted from ancient fossils could be cloned and used to resurrect an extinct species. Comment on the practicality of this idea.

Question 72

Fluorouracil is a structural analogue of thymine. The fluorine promotes enolization. How is this effect used in the treatment of cancer?

Question 73

There are six million base pairs in the human genome. Each bp is 0.3 nm in length. Calculate the total length of the DNA in a single cell. Assuming that there are 10¹⁴cells in the human body calculate the total length of the DNA. How does this estimate compare to the distance from the earth to the sun (1.5 x 10⁸ km)?

Question 74

A DNA sample contains 21% adenine. What is the complete percentage composition of the bases in DNA?