Deck 2: DNA: The Genetic Material

Question 1

What did Watson and Crick deduce about the three-dimensional structure of DNA?

A)There is a repeating pattern every 3.4 nm and every 0.34 nm.
B)It is a double-stranded helix.
C)It contains a lot of phosphorus.
D)It is a large molecule.
E)It consists of supercoiled chromatin.

Answer 1

B

Question 2

A Barr body is an example of

A)constitutive euchromatin.
B)facultative euchromatin.
C)facultative heterochromatin.
D)a nucleosome.
E)constitutive heterochromatin.

Answer 2

C

Question 3

Who used radioactively labeled T2 bacteriophage to confirm the identity of the transforming principle?

A)Griffith
B)Hershey and Chase
C)Avery
D)Gierer and Schramm
E)Beadle and Tatum

Answer 3

B

Question 4

The C-value is the amount of DNA in a

A)haploid genome.
B)diploid genome.
C)bacterial genome.
D)eukaryotic genome.
E)cell's nucleus.

Question 5

The definition of transformation is

A)the shift of genetic information from DNA to protein.
B)the genetic alteration of an organism.
C)the uptake of genetic information by a cell from the environment.
D)Both B and C
E)None of these

Question 6

What did the X-ray diffraction patterns initially reveal about the DNA molecule?

A)It is of uniform diameter and has a helical structure.
B)It is a helical molecule with paired bases in the center.
C)It is double-stranded with antiparallel strands.
D)It is acidic,phosphorus-rich,and large.
E)It contains hereditary information.

Question 7

The chromosome of most prokaryotes differs from those of eukaryotes in that

A)the prokaryotic chromosome is linear,while the eukaryotic chromosome is circular.
B)the prokaryotic chromosome is circular,while the eukaryotic chromosome is linear.
C)the prokaryotic chromosome does not replicate before mitosis,while the eukaryotic chromosome does.
D)the prokaryotic chromosome does not contain genes,while the eukaryotic chromosome does.
E)the prokaryotic chromosome is not necessary for the organism's survival,while the eukaryotic chromosome is.

Question 8

Which part of the T2 bacteriophage entered E.coli cells in the experiment which confirmed the identity of the transforming principle?

A)The RNA
B)The DNA
C)The whole virus
D)The protein coat
E)No part

Question 9

In Griffith's experiment involving the transformation of Streptococcus pneumoniae,

A)the R strain was virulent.
B)the S strain was virulent.
C)both the R and S strains were virulent.
D)the R strain had a protein capsule.
E)the S strain had a protein capsule.

Question 10

Topoisomerases function to

A)remove nucleotides from DNA.
B)join DNA pieces together.
C)twist DNA molecules.
D)attach DNA loops to scaffold proteins.
E)move chromosomes along spindle fibers.

Question 11

Certain ________ have RNA for their genetic material.

A)bacteria
B)viruses
C)plants
D)eukaryotes
E)prokaryotes

Question 12

Complementary base-pairing allows for

A)spontaneous mutations to occur.
B)genes to be expressed as a phenotype.
C)DNA to serve as its own template for replication.
D)replication to be semiconservative.
E)covalent bonds to form between the opposite bases.

Question 13

The displacement loop (D-loop)may be a characteristic of

A)centromeres.
B)telomeres.
C)A-DNA.
D)B-DNA.
E)Z-DNA.

Question 14

Antiparallel means that

A)the two polynucleotide chains run in opposite directions.
B)each DNA molecule consists of one old and one new strand.
C)opposite strands are held together by base pairing.
D)the helix twists to the right.
E)there is complementary base-pairing.

Question 15

Which of the following are the purine nucleotides in DNA?

A)Adenine and thymine
B)Cytosine and guanine
C)Adenine and cytosine
D)Guanine and adenine
E)Thymine and uracil

Question 16

Loosely aggregated DNA bound to proteins in a eukaryotic cell is called

A)chromosomes.
B)chromatin.
C)chromatid.
D)centromere.
E)nucleoid.

Question 17

Which form of DNA is a left-handed double helix?

A)A-DNA
B)B-DNA
C)L-DNA
D)R-DNA
E)Z-DNA

Question 18

What was the transforming principle isolated in Griffith's experiment?

A)Protein
B)RNA
C)DNA
D)Virus
E)Polysaccharide

Question 19

Which of the following is a nonhistone protein found in chromatin?

A)H1
B)HMG
C)H2A
D)H5
E)All of these

Question 20

What is the C-value paradox,and what is its cause?

Question 21

In Griffiths' transformation experiments,under what conditions did the injected mice die?

Question 22

The virus first shown to have RNA as its genetic material was tobacco mosaic virus (TMV).

Question 23

Hershey and Chase used radioactive sulfur to label the genetic material of bacteriophages.

Question 24

By weight,the amount of DNA in chromatin is less than that of histone.

Question 25

The genome of most prokaryotes consists of moderately repetitive DNA.

Question 26

DNA and RNA both contain phosphate and ribose.

Question 27

In a strand of DNA,a hydrogen bond connects the phosphate group of one nucleotide to the sugar of the adjacent nucleotide.

Question 28

What are the three necessary characteristics of the hereditary molecule in cells?

Question 29

One of the strands in a DNA double helix has the nucleotide sequence 5'-ACCTGCTACGG-3'.What is the sequence of the complementary DNA strand?

Question 30

The more condensed a part of a chromosome is,the more likely it is that the genes in that region will be active.

Question 31

In eukaryotes,the greatest relative amount of tandemly repeated DNA is associated with centromeres and telomeres.

Question 32

The genome of the T-even family of bacteriophage consists of single-stranded RNA.

Question 33

What is the function of dispersed repeated sequences such as SINEs and LINEs in eukaryotes?

Question 34

Define Chargaff's rules of the base composition of DNA.

Question 35

Borrelia burgdorferi is a bacterium whose genome consists of one large and several small linear chromosomes.

Question 36

How could you test whether the transforming ability of a cell extract was due to DNA or RNA?

Question 37

Name the constituent parts of a nucleoside and a nucleotide.

Question 38

Describe the differences between heterochromatin and euchromatin in chromosomes.Are there any situations in which one can be changed into the other?

Question 39

Which nucleotide is absent in RNA?

A)Adenine
B)Guanine
C)Uracil
D)Cytosine
E)Thymine

Question 40

If the human egg has 3 billion base pairs,how many nucleosomes will be present in the nucleus of a human somatic cell?

Question 41

What is the role of centromeres and telomeres?

Question 42

Describe the packing of chromatin from the 10-nm to the 30-nm fiber stage.What is the role of histones?

Question 43

If the base pairs in a DNA helix are 0.34 nm apart,and a complete (360°)turn of the helix takes 3.4 nm,how many base pairs per turn are there in a DNA molecule?

Question 44

The DNA phage ΦΧ174 was found to have a ratio of bases of 25A:33T:24G:18C.This departs from the usual A/T = 1 and G/C = 1 ratios.How can you explain this?

Question 45

Why are the amino acid sequences of eukaryotic histones so similar to one another,even among distantly related species?