Bio111 DNA exam

A DNA specimen that contains 30% guanine has ________ thymine.

20%

Reverse transcriptase is an enzyme that can synthesize DNA from an RNA template. What DNA sequence is produced from an RNA molecule with the sequence 5'AUUGACGGU3'?

3'TAACTGCCA5'

What is the complement DNA strand to 5′-ATTCGGTGA-3′?

3′-TAAGCCACT-5′

Which of the following functions of genetic material accounts for the rapid growth of cancer cells? Select one: a. Ability to replicate b. Ability to replicate and transmission to the next generation c. Transmission to the next generation d. Information storage e. Production of variation within and between species

Ability to replicate and transmission to the next generation

All of the following nucleotide bases are pyrimidines EXCEPT Select one: a. cytosine. b. cytosine and thymine. c. adenine. d. uracil. e. thymine.

Adenine

Without the work of Rosalind Franklin, Watson and Crick would not have known

All of the above

Without data from the base composition studies of Chargoff, what might Watson and Crick's modeling studies have erroneously concluded?

Any purine could pair with any pyrimidine

Who discovered that DNA was the genetic material or transforming factor that could convert nonvirulent R-type Streptococcus pneumoniae bacterium to the virulent S-type?

Avery, MacLeod and McCarty

Which of the following is FALSE when comparing RNA and DNA?

Both are composed of identical nucleotides

Which of the following relationships about nucleotide composition in DNA is TRUE? Select one: a. C+G=A+T b. C=T c. C+A=G+T d. C=A e. G=T

C+A=G+T

Which of the following is the highest (or most complex) level of structure for genetic material? Select one: a. DNA b. gene c. nucleotide d. double helix e. chromosome

Chromosome

All of the following are critical factors for DNA replication on the leading strand EXCEPT?

DNA Ligase

Which molecule is responsible for separating double-stranded DNA into single strands?

DNA helicase

The function(s) of DNA polymerase includes which of the following?

DNA synthesis, DNA proofreading, and removes RNA primers and fills in the gaps

Which of the following scientist-discoveries is mismatched?

Griffith-Chromosomes

Which molecule catalyzes covalent bond formation between fragments of DNA. Select one: a. ligase b. primase c. helicase d. nuclease e. polymerase

Helicase

Which of the following functions of genetic material accounts for the appropriate expression of proteins? Select one: a. Ability to replicate b. Ability to replicate and transmission to the next generation ] c. Transmission to the next generation d. Information storage e. Production of variation within and between species

Information Storage

Which of the following functions of genetic material accounts for the high level of protection it is afforded by eukaryotic cells, such as multiple DNA repair mechanisms and storage within the double membrane of the nucleus

Information Storage

Which of the following functions of genetic material accounts for hemoglobin proteins to be expressed in blood (bone marrow) and myoglobin proteins to be expressed in muscle tissue?

Information storage

Which of the following statements best describes DNA polymerase? Select one: a. It is an enzyme that polymerizes the DNA and keeps the replication fork open. XXX b. It is an enzyme required to glue pieces of DNA fragments together. XXX c. It is an enzyme required to produce a primer needed for DNA replication. XXX d. It is an enzyme that catalyzes the addition of nucleotides to the 5′ end of a growing DNA strand. XXX e.It is an enzyme required to produce a primer needed for DNA replication.

It is an enzyme required to produce a primer needed for DNA replication.

______________ are made in replicating the lagging strand of DNA, but are not made during leading strand DNA replication.

Okazaki fragments

Which of the following statements is FALSE? Select one: a. A eukaryotic genome is made up of many DNA molecules b. A DNA double helix is composed of both covalent bonds and hydrogen bonds c. A strand of DNA is made up of many nucleotides d. All of these are TRUE e. One chromosome is made up of many DNA molecules

One chromosome is made up of many DNA molecules??????

The nucleotides within DNA are composed of a Select one: a. phosphate group, deoxyribose sugar, and nitrogenous base. b. phosphate group, hexose sugar, and nitrogenous base. c. sulfur group, ribose sugar, and nitrogenous base. d. phosphate group, ribose sugar, and nitrogenous base. e. sulfur group, deoxyribose sugar, and nitrogenous base.

Phosphate group, deoxyribose sugar, and nitrogenous base.

Which of the following statements in TRUE? Select one: a. Radial loops are formed due to interactions between histone proteins and intermediate filaments. b. Interphase chromosomes are loosely compacted, overlapping, and intertwined with each other within the nucleus. c. None of these are TRUE XXX d. Interphase chromosomes are also known as euchromatin. Condensed, metaphase chromosomes are also known as heterochromatin. e. Interphase chromosomes are loosely compacted and do not associate with histones until the cell is preparing to divide. xxx

Radial loops are formed due to interactions between histone proteins and intermediate filaments.

Which of the following statements about the structure or composition of DNA is FALSE?

The amount of thymine closely approximates that of guanine within a particular organism.

Which of the following is NOT a criterion for an organism's genetic material?

The genetic material must be dynamic, changing rapidly in response to changes in the environment.

Which of the following statements is TRUE? Select one: a. The lagging strand is synthesized in a semiconservative fashion while the leading strand is synthesized in a conservative fashion b. The lagging strand has a higher mutation rate than the leading strand XXX c. The leading strand is replicated continuously for the entire length of the chromosome, while the lagging strand has multiple origins of replication XXX d. None of these are true XXX e. Synthesis of the lagging strand requires more helicase enzymes than synthesis of the leading strand. XXX

The lagging strand is synthesized in a semiconservative fashion while the leading strand is synthesized in a conservative fashion

Some bacteria have been found to have much higher rates of mutation than other members of their populations; they are termed "mutators." What do you think is the reason for their faster rates of mutation? Select one: a. Their DNA polymerase has compromised 5' to 3' polymerase function. b. Their DNA polymerase has compromised 3' to 5' exonuclease function. c. They are incapable of bacterial transformation. d. They have much smaller genomes than regular bacteria. e. They are much better at bacterial transformation than regular bacteria. Incorrect

Their DNA polymerase has compromised 3' to 5' exonuclease function.

The enzyme that attaches DNA sequences at the ends of eukaryotic chromosomes in order to prevent chromosome shortening is called _____.

Topoisomerase XXX

Which of the following characteristics of genetic material accounts for the need to get a flu vaccine every year, but a polio vaccine once in a life time? Select one: a. Replication and Transmission b. Variation c. Replication d. Information e. Transmission

Variation

Which of the following characteristics of genetic material accounts for the phenomenon of natural selection?

Variation

Which purine base forms 3 hydrogen bonds when binding its complementary nucleotide base?

guanine

The protein of T2 bacteriophage is labeled with 35S and the DNA with 32P. Where would one detect most of the 32P if the T2 bacteriophage were allowed to infect the bacteria?

inside the infected bacteria

Beginning with the simplest level of structure, which order of organization of genetic material is CORRECT?

nucleotide, DNA, gene, chromosome, genome

Bacteria are grown in 15N (heavy) medium and then transferred to 14N (light) medium and are allowed to replicate for 1 generation. The DNA is subsequently isolated and centrifuged in a CsCl2 gradient to yield what type of gradient band(s)?

one half-heavy (intermediate to heavy and light) band

Bacteria are grown in 15N (heavy) medium and then transferred to 14N (light) medium and are allowed to replicate for 2 generations. The DNA is subsequently isolated and centrifuged in a CsCl2 gradient to yield what type of gradient band(s)?

one light and one half-heavy band

Which of the following proteins-functions is mismatched?

topoisomerase-separates double-stranded DNA into single strands

How many replication forks are there at an origin of replication? Select one: a. 3 b. 1 c. 4 d. 5 e. 2

2

Which of the following statements about DNA replication is INCORRECT? Select one: a. It proceeds with the addition of new nucleotides to the 3′ end of a growing DNA strand. b. It begins at multiple origins of replication sites along eukaryotic chromosomes. c. Each strand within the DNA double helix is used as a template for synthesis of a new strand. d. It requires that each strand in the double helix be separated from the other. e. It is powered by the hydrolysis of ATP.

It is powered by the hydrolysis of ATP.

The mechanism of DNA replication is

Semiconservative

Which of the following statements about telomeres is INCORRECT? Select one: a. Telomeres would be longer in cells of older than younger individuals. b. Telomeres are produced by telomerase. c. Telomeres are short repeat sequences. d. Telomeres are crucial to the viability of a cell that replicates often. e. Telomeres are found at the ends of chromosomes.

Telomeres would be longer in cells of older than younger individuals.

Type S Streptococcus pneumoniae bacterium is lethal and will kill its host. If heat inactivated the S strain dies and becomes nonlethal. Type R Streptococcus pneumoniae is a nonvirulent strain of bacteria. What would occur if one were to inject both the R strain and heat-killed S strains into a host organism such as the mouse?

The R strain would be transformed into the virulent S strain and kill the host.

Why is there a need to produce Okazaki fragments on the lagging strand, but not on the leading strand of DNA? a. It is substantially more efficient to make several shorter strands rather than one longer strand of DNA. b. The two parental strands of DNA are antiparallel and DNA polymerase makes DNA in the 5′ to 3′ direction only. c. By having one leading strand and one lagging strand the cell can limit the amount of DNA polymerase used for chromosomal replication. d. The leading strand opens first, and so Okazaki fragments are not needed. The lagging strand unwinds second resulting in the need to produce Okazaki fragments. e. There is not enough cellular DNA ligase for bonding Okazaki fragments together if they were produced from both parental strands.

The two parental strands of DNA are antiparallel and DNA polymerase makes DNA in the 5′ to 3′ direction only.

During the DNA replication process, which of the following organisms would have the fewest origins of replication per cell?

a rapidly dividing Streptococcus bacterium

What was one of the pieces of evidence most critical to the discovery of DNA structure?

an X-ray diffraction pattern suggesting a double helix shape