Exam 3 Practice of Quizzes

DNA consists of how many polynucleotide chains? a.)4 b.)1 c.)3 d.)2

2

The figure shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway? a.)3 b.)2 c.)1 d.)5

2

A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the corresponding codon for the mRNA that is transcribed? a.)3′-UCA-5′ b.)5′-UCA-3′ c.)3′-ACU-5′ d.)5′-AGT-3′

3′-UCA-5′

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules? a.)A + T = G + C b.)A = G c.)A + G = C + T d.)A = C

A + G = C + T

A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in "heavy" (radioactive) nitrogen (15N) for several generations and then transfer them to 14N medium. Which pattern in the figure would you expect if the DNA was replicated in a conservative manner? a.)D b.)A c.)B d.)C

B

What is the first step in translation? a.)Binding of DNA polymerase b.)Binding of RNA polymerase c.)Binding of the small ribosomal subunit to mRNA d.)Release of a polypeptide

Binding of the small ribosomal subunit to mRNA

In bacteria, which of the following proteins is responsible for removing nucleotides from the RNA primer that is used for initiation DNA synthesis? a.)DNA pol III b.)Primase c.)DNA pol I d.)DNA ligase

DNA pol I

According to the central dogma, the correct sequence of events that eventually generates proteins is: a.)RNA → Transcription → DNA → Translation → Protein b.)DNA → Translation → Protein → Transcription → RNA c.)DNA → Transcription → RNA → Translation → Protein d.)RNA → Translation → Protein → Transcription → DNA

DNA → Transcription → RNA → Translation → Protein

A researcher is studying DNA replication in a few new organisms. During this process, she notes multiple origins of replication, in addition to "overhanging" regions on the ends of linear chromosomes, which are extended by an enzyme. The organisms are likely: a.)neither prokaryotes or eukaryotes b.)prokaryotes c.)eukaryotes d.)both prokaryotes and eukaryotes

Eukaryotes

What is the name of the mutation that alters the codon reading window so that it reads the triplicate codon code incorrectly? a.)Triplet-transfer mutation b.)Frame-shift mutation c.)Lateral-shunt mutation d.)Window-move

Frame-shift mutation

Who performed classic experiments that supported the semiconservative model of DNA replication? a.)Franklin and Wilkins b.)Hershey and Chase c.)Watson and Crick d.)Meselson and Stahl

Meselson and Stahl

Which organelle stores most of the eukaryotic genome? a.)Endoplasmic reticulum b.)Nucleus c.)Chloroplast d.)Mitochondria

Nucleus

What type of bond links the sugars in DNA molecule? a.)Peptide bond b.)Hydrogen bond c.)Glycosidic bond d.)Phosphodiester bond

Phosphodiester bond

RNA splicing: a.)Produces a functional transfer RNA b.)Is a way that gene expression is inhibited c.)Produces a functional messenger RNA d.)Is a type of post-translational modification

Produces a functional messenger RNA

In his work with pneumonia-causing bacteria and mice, Griffith found that ________. a.)some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic b.)the protein coat from pathogenic cells was able to transform nonpathogenic cells c.)the polysaccharide coat of bacteria caused pneumonia d.)heat-killed pathogenic cells caused pneumonia

Some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic

What do nonsense mutations do? a.)They flip one codon backwards so that it codes for a different amino acid b.)They change every codon to its opposite, complementary sequence c.)They change a codon previously coding for an amino acid into a stop codon d.)They make a codon repeat multiple times in a row

They change a codon previously coding for an amino acid into a stop codon

Which of the following is not present in mRNA? a.)Guanine b.)Thymine c.)Uracil d.)Adenine

Thymine

In bacteria, what is the function of DNA polymerase III? a.)to add nucleotides to the 3' end of a growing DNA strand b.)to seal together the broken ends of DNA strands c.)to degrade damaged DNA molecules d.)to unwind the DNA helix during replication

To add nucleotides to the 3' end of a growing DNA strand

Which of the following statements is true about protein synthesis in prokaryotes? a.)Translation can begin while transcription is still in progress. b.)Extensive RNA processing is required before transcripts can be translated. c.)Protein targeting to cellular organelles requires recognition of signal sequences. d.)Translation requires no initiation or elongation factors.

Translation can begin while transcription is still in progress.

A single codon specifies: a.)an amino acid b.)a gene c.)a complementary nucleotide d.)a mRNA

an amino acid