Question 1

Hershey and Chase determined whether DNA or protein was the genetic material in bacteriophages. What isotope did they use to label the viral protein?

Accepted Answer

A)  14C 
B)  15N 
C)  18O 
D)  32P 
E)  35S 
A)  14C 
B)  15N 
C)  18O 
D)  32P 
E)  35S E

Question 2

Which of the following is NOT an example of secondary structure in nucleic acids?

Accepted Answer

A)  hairpin 
B)  stem 
C)  H-DNA 
D)  B-DNA 
E)  C-DNA 
A)  hairpin 
B)  stem 
C)  H-DNA 
D)  B-DNA 
E)  C-DNA E

Question 3

While investigating a gene that might be responsible for pathogen resistance in the plant Arabidopsis, you discover that many of the nucleotides in the gene sequence are methylated. (1) Which nucleotide (A, T, C, or
G) is most likely to be methylated? (2) Draw the structure of this methylated nucleotide. (3) What might this methylation do to the function of this gene?

Accepted Answer

(1) The nucleotide most likely to be methylated is cytosine (C). (2) The structure of methylated cytosine involves the addition of a methyl group (CH3) to the fifth carbon of the cytosine ring. (3) Methylation of the gene sequence may affect the function of the gene by altering its expression or regulation. It could also potentially affect the binding of transcription factors or other proteins to the gene, leading to changes in its activity or response to pathogens. Additionally, methylation can also impact the stability of the gene sequence and its ability to be transcribed into RNA.

Question 4

You are a research assistant in a lab that studies nucleic acids. Your advisor gave you four tubes for analysis. Each of these tubes differs in its contents by the source of its nucleic acids: mouse cytoplasm (single-stranded RNA), yeast nuclei (double-stranded DNA), rotavirus (double-stranded RNA), and parvovirus (single-stranded DNA). The approximate nucleotide base composition of each sample is given in the table below. $$\begin{array} { | l | r | r r r | r } 
\hline \text { Tube } & \text { A } & \mathbf { C } & \text { U } & \text { T } & \mathbf { G } \
\hline 1 & 32 & 17 & 0 & 32 & 19 \
\hline 2 & 34 & 16 & 15 & 0 & 35 \
\hline 3 & 30 & 21 & 0 & 26 & 23 \
\hline 4 & 33 & 16 & 34 & 0 & 17 \
\hline
\end{array}$$ 
-Which samples would be destroyed by a DNase?

Accepted Answer

A)  tubes 1 and 3 
B)  tubes 2 and 4 
C)  tubes 1 and 2 
D)  tubes 3 and 4 
E)  all the tubes 
A)  tubes 1 and 3 
B)  tubes 2 and 4 
C)  tubes 1 and 2 
D)  tubes 3 and 4 
E)  all the tubes

Question 5

How did Avery, MacLeod, and McCarty contribute to our understanding of DNA?

Accepted Answer

A)  used X-ray diffraction to examine the structure of DNA 
B)  determined that DNA contains four different nitrogenous bases 
C)  found that "the transforming principle" is destroyed by enzymes that hydrolyze DNA 
D)  found that the phosphorus-containing components are the genetic material of phages 
E)  discovered "the transforming principle" that could genetically alter bacteria 
A)  used X-ray diffraction to examine the structure of DNA 
B)  determined that DNA contains four different nitrogenous bases 
C)  found that "the transforming principle" is destroyed by enzymes that hydrolyze DNA 
D)  found that the phosphorus-containing components are the genetic material of phages 
E)  discovered "the transforming principle" that could genetically alter bacteria

Question 6

What is the difference in hydrogen bonding between A/T pairs versus G/C pairs?

Accepted Answer

A)  A/T pairs have one more hydrogen bond than G/C pairs. 
B)  G/C pairs have one more hydrogen bond than A/T pairs. 
C)  A/T pairs have two more hydrogen bonds than G/C pairs. 
D)  G/C pairs have two more hydrogen bonds than A/T pairs. 
E)  G/C pairs have three more hydrogen bonds than A/T pairs. 
A)  A/T pairs have one more hydrogen bond than G/C pairs. 
B)  G/C pairs have one more hydrogen bond than A/T pairs. 
C)  A/T pairs have two more hydrogen bonds than G/C pairs. 
D)  G/C pairs have two more hydrogen bonds than A/T pairs. 
E)  G/C pairs have three more hydrogen bonds than A/T pairs.

Question 7

Which diagram shows a nucleotide as it would appear in DNA?

Accepted Answer

A)  diagram A 
B)  diagram B 
C)  diagram C 
D)  diagram D 
E)  diagram E 
A)  diagram A 
B)  diagram B 
C)  diagram C 
D)  diagram D 
E)  diagram E

Question 8

Which of the following is NOT a key characteristic that genetic material must possess?

Accepted Answer

A)  Genetic material must contain complex information. 
B)  Genetic material must replicate faithfully. 
C)  Genetic material must encode the phenotype. 
D)  Genetic material must have the capacity to vary. 
E)  Genetic material must contain nitrogen but not sulfur. 
A)  Genetic material must contain complex information. 
B)  Genetic material must replicate faithfully. 
C)  Genetic material must encode the phenotype. 
D)  Genetic material must have the capacity to vary. 
E)  Genetic material must contain nitrogen but not sulfur.

Question 9

Draw a dinucleotide of two DNA molecules. Label the 5' end, the 3' end, and the phosphodiester bond. Draw the ring(s) of a purine base on one nucleotide and a pyrimidine base on the other. Then label them.

Accepted Answer

To draw a dinucleotide of two DNA molecu

Question 10

Heat can disrupt hydrogen bonding between DNA strands. Which of the following DNA strands would denature at the LOWEST temperature?

Accepted Answer

A)  10% AT and 90% GC 
B)  30% AT and 70% GC 
C)  50% AT and 50% GC 
D)  70% AT and 30% GC 
E)  90% AT and 10% GC 
A)  10% AT and 90% GC 
B)  30% AT and 70% GC 
C)  50% AT and 50% GC 
D)  70% AT and 30% GC 
E)  90% AT and 10% GC

Question 11

Which of the following is NOT characteristic of A-form DNA compared to B- or Z-form DNA?

Accepted Answer

A)  has right-handed helixes 
B)  exists when less water is present 
C)  is long and narrow 
D)  has 50% purines, 50% pyrimidines 
A)  has right-handed helixes 
B)  exists when less water is present 
C)  is long and narrow 
D)  has 50% purines, 50% pyrimidines

Question 12

The concept that genetic information passes from DNA to RNA to protein is called the:

Accepted Answer

A)  central dogma. 
B)  nitrogenous base. 
C)  transforming principle. 
D)  polynucleotide strand. 
E)  reverse transcription. 
A)  central dogma. 
B)  nitrogenous base. 
C)  transforming principle. 
D)  polynucleotide strand. 
E)  reverse transcription.

Question 13

While investigating a gene that might be responsible for pathogen resistance in the plant Arabidopsis, you discover that many of the nucleotides in the gene sequence are methylated. Which nucleotide is MOST likely to be methylated?

Accepted Answer

A)  A 
B)  T 
C)  C 
D)  G 
A)  A 
B)  T 
C)  C 
D)  G

Question 14

How did Chargaff's rules contribute to Watson and Crick's elucidation of the structure of DNA?

Accepted Answer

A)  The rules suggested an equal concentration of sugars and phosphates. 
B)  The rules suggested the amounts of all four bases were equal. 
C)  The rules suggested the base-pairing combinations of adenine with thymine and guanine with cytosine. 
D)  The rules suggested that each base corresponds to an amino acid. 
A)  The rules suggested an equal concentration of sugars and phosphates. 
B)  The rules suggested the amounts of all four bases were equal. 
C)  The rules suggested the base-pairing combinations of adenine with thymine and guanine with cytosine. 
D)  The rules suggested that each base corresponds to an amino acid.

Question 15

While doing research on deep-sea vents, you discover a very simple new life form. After some initial analysis, you find that this life form contains small fragments of DNA, small complementary RNA fragments, and proteins. Fortuitously, you collected two strains, one that is purple and one that is yellow. 
-You decide to attempt a transformation: seeing if you can covert the purple form into the yellow form. From which sample(s) would you find some yellow form? (Select all that apply.)

Accepted Answer

A)  live yellow form 
B)  heat-killed yellow form 
C)  purple form 
D)  heat-killed purple form 
A)  live yellow form 
B)  heat-killed yellow form 
C)  purple form 
D)  heat-killed purple form

Question 16

You are a researcher studying the genetic basis of colon cancer. You have been working with a colon cancer cell line to determine the expression levels of different genes that might contribute to cancer formation. You obtain the DNA methylation status of five genes of interest (the data are shown in the table below). The plus (+) sign indicates the level of DNA methylation; more plus signs correlates with increased methylation levels. $$\begin{array} { l r r } 
\hline \text { Gene } & \text { Methylation levels } & \
\hline 1 & + + \
\hline 2 & + + + + + \
\hline 3 & + + + \
4 & + + \
5 & +
\end{array}$$ Based on the information shown above, which gene would you predict to have the highest rate of transcription?

Accepted Answer

A)  gene 1 
B)  gene 2 
C)  gene 3 
D)  gene 4 
E)  gene 5 
A)  gene 1 
B)  gene 2 
C)  gene 3 
D)  gene 4 
E)  gene 5

Question 17

Which circle shows a bond that would also be found in an RNA transcribed from one strand of this DNA?

Accepted Answer

A)  circle a 
B)  circle b 
C)  circle c 
A)  circle a 
B)  circle b 
C)  circle c

Question 18

Two double-stranded fragments of DNA are exactly the same length. At 89°C, fragment A has completely denatured, which means that the two strands have separated. At that temperature, fragment B is still double-stranded. How might these fragments differ to result in different denaturation temperatures?

Accepted Answer

A)  Fragment A has a higher C+C content than fragment B. 
B)  Fragment B has a higher C+G content than fragment A. 
C)  Fragment A has a secondary structure of B form, while fragment B is an A form. 
D)  Fragment B is methylated more than fragment A. 
A)  Fragment A has a higher C+C content than fragment B. 
B)  Fragment B has a higher C+G content than fragment A. 
C)  Fragment A has a secondary structure of B form, while fragment B is an A form. 
D)  Fragment B is methylated more than fragment A.

Question 19

Describe two characteristics of Z-DNA that distinguish it from B-DNA.

Accepted Answer

Z-DNA is a left-handed helical form of D

Question 20

Hershey and Chase determined whether DNA or protein was the genetic material in bacteriophages. What isotope did they use to label the viral DNA?

Accepted Answer

A)  14C 
B)  15N 
C)  18O 
D)  32P 
E)  35S 
A)  14C 
B)  15N 
C)  18O 
D)  32P 
E)  35S

Exam 10: DNA: the Chemical Nature of the Gene

Hershey and Chase determined whether DNA or protein was the genetic material in bacteriophages. What isotope did they use to label the viral protein?

Which of the following is NOT an example of secondary structure in nucleic acids?

How did Avery, MacLeod, and McCarty contribute to our understanding of DNA?

What is the difference in hydrogen bonding between A/T pairs versus G/C pairs?

Which diagram shows a nucleotide as it would appear in DNA?

Which of the following is NOT a key characteristic that genetic material must possess?

Draw a dinucleotide of two DNA molecules. Label the 5' end, the 3' end, and the phosphodiester bond. Draw the ring(s) of a purine base on one nucleotide and a pyrimidine base on the other. Then label them.

Heat can disrupt hydrogen bonding between DNA strands. Which of the following DNA strands would denature at the LOWEST temperature?

Which of the following is NOT characteristic of A-form DNA compared to B- or Z-form DNA?

The concept that genetic information passes from DNA to RNA to protein is called the:

While investigating a gene that might be responsible for pathogen resistance in the plant Arabidopsis, you discover that many of the nucleotides in the gene sequence are methylated. Which nucleotide is MOST likely to be methylated?

How did Chargaff's rules contribute to Watson and Crick's elucidation of the structure of DNA?

Which circle shows a bond that would also be found in an RNA transcribed from one strand of this DNA?

Describe two characteristics of Z-DNA that distinguish it from B-DNA.

Hershey and Chase determined whether DNA or protein was the genetic material in bacteriophages. What isotope did they use to label the viral DNA?

Introduction to Genetics

Chromosomes and Cellular Reproduction

Basic Principles of Heredity

Sex Determination and Sex-Linked Characteristics

Extensions and Modifications of Basic Principles

Pedigree Analysis, Applications, and Genetic Testing

Linkage, Recombination, and Eukaryotic Gene Mapping

Chromosome Variation

Bacterial and Viral Genetic Systems

Chromosome Structure and Organelle Dna

DNA Replication and Recombination

Transcription

Rna Molecules and Rna Processing

The Genetic Code and Translation

Control of Gene Expression in Prokaryotes

Control of Gene Expression in Eukaryotes

Gene Mutations and Dna Repair

Molecular Genetic Analysis and Biotechnology

Genomics and Proteomics

Epigenetics

Developmental Genetics and Immunogenetics

Cancer Genetics

Quantitative Genetics

Population Genetics

Evolutionary Genetics

Filters