exam 3: genetics final

Why might heat-killed bacteria be useful as a vaccine?
A) it can cause a lethal infection
B) Heat degradation of proteins changes their shape
C) Molecules from the cell surface are still intact and can provoke an immune response
D) DNA molecules can trans

C) Molecules from the cell surface are still intact and can provoke an immune response

What occurred in the transformation observed by Griffith?
A) A smooth strain underwent mutation to convert it to a rough strain
B) A smooth strain passed genetic information to a rough strain
C)A rough strain underwent mutation to covert it to a smooth st

A smooth strain passed genetic information to a rough strain

Which of the following is a line of evidence that indicates triplex DNA may exist in vivo?
A) triples DNA can be synthesized in the lab
B) triplex DNA follows certain base pairing rules
C) Triplex DNA is recognized by certain proteins present in cells
D)

Triplex DNA is recognized by certain proteins present in cells

Which of the following is INCORRECT regarding the T2 bacteriophage?
A) it requires a host cell for replication
B) the phage attaches to the cell wall of a target bacteria
C)The phages injects the protein coat into the host cell
D) the new phages are forme

The phages injects the protein coat into the host cell

Which of the following is correct regarding the Hershey-Chase experiments?
A) The radioactively labeled the protein coat of the bacteriophage with 35S
B) The radioactively labeled the DNA of the bacteriophage with 32P
C) The results of the experiment indi

all of these choices are correct

The building blocks of DNA are called_______
A) amino acids
B) codons
C) nucleotide
D) alleles

nucleotides

All nucleotides contain which of the following?
A) a phosphate group
B) a five carbon sugar
C) one of five nitrogenous bases
D) all of these choices are correct

all of these choices are correct

DNA differs from RNA in which of the following ways?
A) the five-carbon sugar it uses
B) The size of the phosphate groups
C) the number of bases attached to the sugar
D) all of these choices are correct

The five carbon sugar it uses

Which of the following is not found in DNA?
A) cytosine
B) guanine
C) thymidine
D) adenine
E) uracil

uracil

The backbone of the DNA molecule is formed by______.
A) peptide bonds
B) ribose sugars
C) nitrogenous bases
D) phosphodiester bonds
E) none of these choices are correct

phosphodiester bonds

According to Chargaff's rule, if the DNA of a species contains 20% adenine, what percent of guanine will it contain?
A) 20%
B) 30%
C) 50%
D) 75%

30%

In the double-helix DNA strand, the adenine on one strand forms a hydrogen bond with a(n)_____ on the other strand.
A) adenine
B) guanine
C)thymine
D) cytosine

thymine

How many bases are necessary to complete one complete twist (360 degrees) of a DNA helix?
A) 5
B) 10
C) 100
D) 1000

10

The fact that the helixes of the DNA strand are arranged in opposite directions gives DNA its ______ characteristics.
A) antiparallel
B) complementary
C) redundant
C) water-soluble

antiparallel

One strand of DNA is 5'-AGGCCTTA-3'. What is the opposite strand?
A) 5'-AGGCCTTA-3'
B)5'- TCCGGAAT-3'
C) 5'- ATTCCGGA-3'
D) 5'-TAAGGCCT-3'

5'- TAAGGCCT-3'

Which of the following DNA forms is the most common in living organisms?
A) A DNA
B) B DNA
C) Z DNA
D) Triplex DNA

B DNA

In the Hershey-Chase experiments, the ______ was labeled using the radioisotope 32P.
A) RNA
B) DNA
C) protein
D) carbohydrates

DNA

The purine base are_____.
A) cytosine, thymine, and uracil
B) adenine and guanine

adenine and guanine

Adenines and thymine form____ hydrogen bonds between them, while cytosine and guanine form_____ bonds.
A) 2,3
B) 3,2

2,3

Which type of gene sequence occupies the most space in the bacterial chromosome?
A) repetitive sequences and introns
B) structural gene sequences
C) intergenic regions

structural gene sequences

Which of the following is a description of chromatin?
A) all the genetic sequences contained by members of a particular species
B) The DNA-protein complex which comprises eukaryotic chromosomes
C) Repetitive sequences contained within the genome of an org

The DNA-protein complex which comprises eukaryotic chromosomes

What is the major function of the telomeres?
A) the prevent chromosomes from fusion with each other
B)The prevent chromosomes from shrinking due to DNA loss during replication
C) They allow chromosomes to segregate properly during cell division
D) both A

Both A and B

How many origins of replication are there in bacteria?
A) 0
B) 1
C) 2
D) more than 2

1

Where is the bacterial chromosomes located?
A) nucleus
B) nucleolus
C) nucleoid
D) nuclear envelope

nucleoid

One would expect heterochromatic regions of DNA to be more compacted than euchromatic regions. True or False?

true

Amphibians have much more DNA in their genomes than that of humans. This is due to
A)they have more repetitive sequences
B) they are more complex than mammals
C) they have more genes
D) They are tetraploid

they have more repetitive sequences

Where do kinetochores attache to chromosomes?
A) telomeres
B) specific genes on the chromosome
C) centromeres
D) they don't attach to DNA

centromeres

Which of the following is found at the end of a eukaryotic chromosome?
A) telomeres
B) centromeres
C) kinetochores

telomeres

What term is used to describe highly repetitive DNA?
A) heterochromatin
B) homochromatin
C) euchromatin
D) prochromatin

heterochromatin

An Alu sequence is an example of what?
A) Retro element
B) transposable element
C) Highly repetitive DNA
D) all of these choices are correct

all of these choices are correct

The majority of the non repetitive genes in an organism are found in which of the following?
A) unique sequences
B) moderately repetitive sequences
C)highly repetitive sequences
D) none of these choices are correct

unique sequences

How many types of histone proteins are there?
A) 4
B) 5
C) 7
D) 8

5

A Barr body is an example of what?
A) constitutive heterochromatin
B) facultative heterochromatin
C) constitutive euchromatin
D) facultative euchromatin

facultative heterochromatin

A nucleosome is a combination of _____ and _____.
A) histone proteins, scaffold proteins
B) RNA, transcription proteins
C) DNA, histone proteins
D) RNA, histone proteins
E) DNA, scaffold proteins

DNA, histone proteins

About how many bases of DNA wrap around a histone complex?
A) < 50
B) 146
C) 250
D) >1,000

146

Which of the following promote the formation of heterochromatin during metaphase?
A) radial loop domains
B) condensing and cohesion
C) 30 nm fibers
D) nucleosomes

condensing and cohesion

Which of the following represents the lowest level of chromosome condensation?
A) radial loop domain
B) 30 nm fibers
C) double helix
D) nucleosome

double helix

Which of the following represents the highest level of chromosome condensation?
A)radial loop domain
B) 30 nm fibers
C) double helix
D) nucleosome
E) heterochromatin

heterochromatin

What is a key difference between DNA polIII and DNA ligase?
A) only DNA PolIII synthesizes phosphoester bonds
B) only DNA ligase synthesizes phosphoester bonds between two nucleotides
C) DNA polIII can synthesize DNA from 3' to 5' and reads template DNA f

DNA ligase can use energy ATP rather than nucleotides

What DNA sequence is required from termination of replication in E.coli?
A) oriC
B) ter
C) tus
D) fork

ter

Which of the following is a description of the proofreading function of DNA polymerase?
A)endonulease cleavage
B) exonuclease cleavage
C) methylation
D)an induced-fit phenomenon
E) all of these

exonuclease cleavage

The purpose of DNA replication is to produce____.
A) two daughter strands
B) two parental strand
C) two template strands
D) none of the above

two daughter strands

Which of the following best describes the mechanism of DNA replication in which both a parental strand and daughter strand are combined following replication?
A) dispersive
B) semi-conservative
C) conservative
D all of the answers are correct

semi-conservative

You have isolated what appears to be alien DNA. While studying its replication, you performed the exact experiment Meselson and Stahl did. After 3 generations, the DNA is subjected to a CsCl gradient and one band appears. What type of replication does thi

dispersive

Bacterial DNA has how many origins of replication?
A) 0
B) 1
C) 10

1

_______ prevents supercoiling ahead the replication.
A) DNA ligase
B) DNA primase
C) topisomerase
D) DNA polymerase I
E) DNA polymerase III

topoisomerase

_______ manufactures a 10-12 segment of RNA.
A) DNA ligase
B) DNA primase
C) topisomerase
D) DNA polymerase I
E) DNA polymerase III

DNA primase

In E.coli, ______ fills in small regions of DNA where RNA primers were located.
A) DNA ligase
B) DNA primase
C) topisomerase
D) DNA polymerase I
E) DNA polymerase III

DNA polymerase I

_________ joins adjacent Okazaki fragments, forming a continuous DNA strand.
A) DNA ligase
B) DNA primase
C) topisomerase
D) DNA polymerase I
E) DNA polymerase III

DNA Ligase

How many DNA polymerases are found in prokaryotes?
A) 5
B) 7
C) 9
D) 12

5

_______ synthesizes the lagging strand of the DNA in E. coli
A) DNA ligase
B) DNA primase
C) topisomerase
D) DNA polymerase I
E) DNA polymerase III

DNA Polymerase III

DNA polymerases add new nucleotides in what direction?
A) 5' to 3' only
B) 3' to 5' only
C) either direction
D) all of the above

5' to 3' only

Okazaki fragments do which of the following?
A) assist in forming the replication fork
B) bind to the otic region
C) assist in the synthesis of DNA from the lagging strand
D) reform the double helix following replication
e) none

assist in the synthesis of DNA from the lagging strand

Which of the following is an example of a processive enzyme in prokaryotes?
A) DNA polymerase I
B) DNA polymerase II
C) DNA Polymerase III
d) DNA helicase

DNA polymerase III

Which of the following stops the replication of DNA in prokaryotes?
A) Tus proteins
B) DNA ligase
C) okazaki fragments
D) rho factor

tus proteins

The proofreading of the DNA occurs in the ______.
A) 5' to 3' direction
B) 3' to 5' direction
C) both direction

3' to 5' direction

GGGCCATTCGAACGTCCGAAAATGCCCCTGAATGAAAATTTTGGCCC. The primer is used for replication in vitro is CCCGGTAAGCTT. Where is the 5' end for the template and primer, respectively?
A) left, left
B) right, left
C) left, right
D) right, right

right, left

The closed promoter complex consists of all of the following except:
A) promoter region of the DNA
B) RNA polymerase
C) transcription factors
D) helicase

helicase

If you have a strain of bacteria that produce nonfunctional sigma factor, which step of transcription would you expect will be affected?
A) These bacteria will be unable to assemble RNA polymerase onto the DNA strand
B) These bacteria will be unable to id

These bacteria will be unable to identify and tightly bind promoter elements

Which statement could NOT describe both eukaryotic and prokaryotic transcription?
A) promoter elements in the DNA are required for polymerase binding
B) RNA polymerase opens a double stranded DNA to expose the template strand
C) RNA polymerase catalyzes R

RNA polymerase catalyzes RNA synthesis from 3' to 5' of the new strand

Following transcription, the RNA has a complementary sequence of which of the following?
A)regulatory sequences
B) the template strand of DNA
C) termination sequences
D) the coding strand of DNA
E ) none of the answers are correct

the template strand of DNA

Which of the following enzymes elonagtes mRNA in eukaryotic transcription?
A) DNA Polymerase I
B) DNA polymerase III
C) RNA polymerase I
D) RNA polymerase II
E) RNA polymerase III

RNA polymerase II

Which of the following forms of RNA encodes the sequence of amino acids for a functional protein?
A) tRNA
B) snRN
C) mRNA
D) rRNA
E) seRNA

mRNA

In prokaryotes, a holozyme is formed when which of the following is added to the core enzyme?
A) start codons
B) B unit
C) B' unit
D) o factor
E) a factor

o factor

which of the following is not an example of a eukaryotic transcription regulatory element?
A) enhancers
B) silencers
C) core promoters
D) cis-acting elements
E) cohesin

cohesin

Which of the following allows the RNA polymerase II to interact with enhancers and silencers?
A) mediator
B) TFIIB
C) TFIID
D) sigma factors
E) noe of the above

mediator

Which of the following DNA regions would contain the information for a functional protein?
A) exons
B) introns
C) enhancers
D) promoters
E0 all of the above

exons

Which of the following provides for a higher level of stability in the mRNA?
A) alternative splicing
B) RNA editing
C) 3' polyA tailing
D) intron trimming

3' polyA tailing

Which of the following processes in mRNA maturation is important for the initiation of translation?
A) alternative splicing
B) RNA editing
C) 5' capping
D) intron trimming

5' capping

What transcripts are made by RNA polymerase I in eukaryotes?
A) mRNA
B) tRNA '
C) 18s rRNA
D) micRNA

18S rRNA

Most eukaryotic genes are collinear. This statement is:
True or false

false

What do both the rho-dependent and rho-independent mechanism of termination have in common?
A) terminate transcription immediately after the stop codon
B) a sequence rich with A-U base pairs
C) both require a helices to separate the DNA-RNA complex
D) For

formation of a stem-loop structure

Alternative splicing allows an organism to ______ in its genome.
A) carry fewer genes
B) carry more genes
C) produce fewer gene products
D) all of the above

carry fewer genes