Deck 4: DNA, RNA, and the Flow of Genetic Information

Question 1

In bacterial mRNA, the initiating AUG codon is preceded several nucleotides away by a purine-rich sequence called the __________________ , which base-pairs with a complementary sequence in an rRNA.

Answer 1

Shine-Dalgarno sequence

Question 2

Each amino acid residue in a protein is encoded by a set of three bases in an mRNA referred to collectively as a(n) __________________.

Answer 2

codon

Question 3

Codons that specify the same amino acid are termed _____.

A) degenerate codons
B) anticodons
C) universal codons
D) synonyms
E) None of the answers is correct.

Answer 3

D

Question 4

mRNAs of higher organisms are formed by splicing together _________________ after removal of intervening sequences.

Question 5

Which molecules that are produced during transcription carry information for use as a template during translation?

A) mRNA
B) tRNA
C) rRNA
D) snRNA
E) DNA

Question 6

A noncoding region within a gene is known as a _____.

A) intron
B) exon
C) missense region
D) split gene
E) None of the answers is correct.

Question 7

In an amino acyl-tRNA, the amino acid is attached to the CCA sequence at the _________ end of the tRNA.

Question 8

__________________ is the most abundant type of RNA in a cell.

Question 9

Each three-base codon encodes a specific _____.

A) DNA nucleotide
B) mRNA nucleotide
C) tRNA nucleotide
D) rRNA nucleotide
E) amino acid

Question 10

The phenomenon that stacked bases in double-helical DNA absorb less UV light than the unstacked bases in single-stranded DNA is referred to as _________________.

Question 11

________________molecules participate in the splicing of mRNA.

Question 12

The process of DNA renaturation after melting is called _____.

A) replication
B) supercoiling
C) hybridization
D) helix nucleation
E) annealing

Question 13

The nucleoside that is composed of a D-ribose linked to a cytosine base is called __________________.

Question 14

In what type of organisms can genetic information flow from RNA to DNA?

A) bacteria
B) viruses
C) cyanobacteria
D) archaea
E) None of the answers is correct.

Question 15

The flow of genetic information from DNA to protein is called _____.

A) replication
B) transcription
C) translation
D) gene expression
E) All of the answers are correct.

Question 16

The temperature at which half of the DNA helical character is lost is referred to as _____.

A) T_h
B) T_m
C) T_0.5
D) T_DNA
E) None of the answers is correct.

Question 17

In DNA and RNA synthesis, the new strand growth is always in the ___________ direction.

Question 18

Who noted that A:T and G:C ratios in DNA are approximately 1:1?

A) James Watson
B) Rosalind Franklin
C) Erwin Chargaff
D) Francis Crick
E) None of the answers is correct.

Question 19

The enzyme that is capable of synthesizing DNA from an RNA template is __________________.

Question 20

Stop codons are read by

A) initiation factors
B) transcription factors
C) release factors
D) elongation factors
E) None of the answers is correct.

Question 21

The sites for intron splicing consensus sequences are often

A) AC-------------------AAAA.
B) GU-------------------AG.
C) AU-------------------GC.
D) All of the answers are correct.
E) None of the answers is correct.

Question 22

The first amino acid in bacterial proteins is

A) Met.
B) fGly.
C) fMet.
D) Gly.
E) None of the answers is correct.

Question 23

The technique(s) used by Franklin and Wilkins to deduce the structure of DNA was

A) absorbance spectrophotometry.
B) electron microscopy.
C) x-ray diffraction.
D) All of the answers are correct.
E) None of the answers is correct.

Question 24

Draw the hydrogen-bonded base pairs of A to T and show why A does not hydrogen bond to C.

Question 25

What is the nucleotide sequence on the DNA template strand that yields the CUA codon for leucine?

A) AUC
B) TAG
C) CTA
D) GAT
E) CUA

Question 26

How does a nucleotide differ from a nucleoside?

A) Nucleosides are found in DNA, whereas nucleotides are found in RNA.
B) Purines are only found in nucleotides.
C) Nucleosides contain only deoxyribose sugars.
D) A nucleotide is a nucleoside with a phosphate ester linked to the sugar.
E) None of the answers is correct.

Question 27

Briefly describe the Meselson and Stahl experiment that indicated that DNA replication is semiconservative.

Question 28

Draw two nucleotides in DNA showing the linkage between the sugars.

Question 29

What advantage do phosphodiesters have compared to other esters?

Question 30

What are the common promoter regions found in bacterial genes?

A) a Hogness box at about -10 and a -35 region
B) a TATA box at about -25 and a CAAT box at about -75
C) a Pribnow box at about -10 and a TATA box at about -25
D) a TATA box at about -25 and a -35 region
E) None of the answers is correct.

Question 31

The advantage(s) to having most genes of higher eukaryotes, such as birds and mammals, be split include

A) the potential for generating related proteins.
B) the preservation of functional units (e.g. catalytic site).
C) the resistance to mutation.
D) the potential for generating related proteins and the preservation of functional units (e.g. catalytic site).
E) None of the answers is correct.

Question 32

What is the approximate error rate in DNA replication?

A) 1 *10 ^{- 8}
B) 1 *10 ^{- 5}
C) 1 *10 ^{- 14}
D) 1 * 10 ^{- 11}
E) None of the answers are correct.

Question 33

The feature(s) of DNA deduced by Watson and Crick included

A) two antiparallel polynucleotide chains coiled in a helix around a common axis.
B) the pyrimidine and purine bases lie on the inside of the helix.
C) the bases are nearly perpendicular to the axis.
D) All of the answers are correct.
E) None of the answers is correct.

Question 34

Features of the genetic code include

A) a codon is defined by three bases.
B) the code overlaps.
C) the code is degenerate.
D) a codon is defined by three bases and the code is degenerate.
E) a codon is defined by three bases and the code overlaps.

Question 35

Ribosomes are composed of

A) DNA.
B) rRNA.
C) protein.
D) DNA and rRNA.
E) rRNA and protein.

Question 36

The chemical forces that contribute to the stability of the DNA due to the base stacking present in the DNA helix are

A) hydrogen bonds.
B) van der Waals.
C) disulfide bonds.
D) van der Waals and disulfide bonds.
E) None of the answers are correct.

Question 37

Although the right-handed double helix is the most well-known DNA structure, DNA can also form

A) triple strands.
B) straight chains.
C) branched chains.
D) left-handed helices.
E) All of the answers are correct.

Question 38

The difference in RNA bases compared to DNA bases is

A) RNA contains A instead of T.
B) RNA contains U instead of G.
C) RNA contains U instead of T.
D) RNA contains A instead of U.
E) None of the answers is correct.

Question 39

Which of the following is correct concerning the adaptor molecule tRNA?

A) tRNA contains an anticodon sequence that serves as the template recognition site.
B) The amino acid is attached to the 5' end of tRNA.
C) tRNA contains a poly A tail at the 3' end.
D) tRNA is the largest RNA in the cell.
E) tRNA serves as the gene in some viruses.

Question 40

Describe the DNA helix proposed by Watson and Crick.

Question 41

Draw how the dNTP is added to a DNA strand at the 3' end.

Question 42

How does RNA polymerase differ from DNA polymerase?

Question 43

What are the minimal components required for DNA replication?

Question 44

What is an advantage of codon degeneracy?

Question 45

Why are deletion and insertion mutations potentially lethal?

Question 46

What are the characteristics of Z-DNA and what does the Z in Z-DNA stand for?

Question 47

What is DNA hybridization?

Question 48

What is a consensus sequence?

Question 49

What are two features of mature eukaryotic mRNA that are unique as compared to prokaryotic mRNA?

Question 50

The genetic code is not universal. Where are exceptions found?