Deck 8: DNA Structure and Chromosomal Organization

Question 1

What is the percentage of individuals who died after contracting the SARS virus?

A) 10
B) 25
C) 50
D) 75
E) 100

Answer 1

C

Question 2

To make a DNA vaccine against SARS, what type of genes were used?

A) Human genes
B) E.coli genes
C) Chimpanzee genes
D) SARS viral genes
E) H1N1 viral genes

Answer 2

D

Question 3

In the Watson-Crick model of DNA structure, the polynucleotide chains are

A) of unequal length.
B) both oriented in the same direction.
C) arranged with the bases on the outside.
D) built with the nucleotides as the backbone.
E) oriented in opposite directions.

Answer 3

E

Question 4

What is the significance of hydrogen bonds in the shape of biological molecules?

A) They are strong bonds that join the atoms of the molecules to each other.
B) They are weak bonds that join the atoms of the molecules to each other.
C) They are weak bonds that play no role in the shape of biological molecules.
D) They are weak bonds that help determine the shape of many molecules because there are so many of them.
E) Hydrogen bonds are only of significance in DNA.

Question 5

Chromatin is an extraction of pure DNA.

Question 6

The 3' end of DNA or RNA ends with a phosphate group.

Question 7

In addition to the nucleosome, DNA in a chromosome has several more levels of folding and compaction.

Question 8

A single DNA molecule runs half the length of a human chromosome; the rest of the chromosome consists of protein.

Question 9

Chromosome territories do not overlap each other.

Question 10

Hershey and Chase's experiment with radioactively labeled viruses made use of the fact that protein, but not DNA, contains

A) phosphorus.
B) iron.
C) sulfur.
D) nitrogen.
E) potassium.

Question 11

RNA differs from DNA in

A) its single-stranded nature.
B) the type of sugar found in the nucleotide.
C) the types of pyrimidine bases.
D) the type of sugar found in the nucleotide, the types of pyrimidine bases, and its single-stranded nature.
E) the types of pyrimidine bases and its single-stranded nature only.

Question 12

In Fredrick Griffith's classic experiments,

A) mice injected with strain R cells died of pneumonia.
B) mice injected with strain S cells died of pneumonia.
C) mice injected with live strain R cells and heat-killed strain S cells died of pneumonia.
D) mice injected with strain S cells, or live strain R cells and heat-killed strain S cells died of pneumonia.
E) mice injected with strain R cells, or live strain R cells and heat-killed strain S cells died of pneumonia.

Question 13

The breaking of the hydrogen bonds in DNA is not necessary for DNA replication to occur.

Question 14

The basic unit of a DNA molecule is the

A) nitrogenous base.
B) sugar-phosphate backbone.
C) amino acid.
D) nucleotide.
E) ribose sugar.

Question 15

What is the current status of DNA vaccines?

A) None has been successfully created.
B) Several have been created but have been found to be ineffective.
C) Several have shown promise in animal studies and are now in clinical trials.
D) Several have passed clinical trials and are awaiting government approval.
E) They are in limited use against a small number of diseases.

Question 16

The results of the experiments of Avery and his colleagues indicate that

A) proteins are antigens.
B) proteins transfer genetic information.
C) capsule formation is mediated by RNA.
D) DNA is the transforming material.
E) DNA replication is semiconservative.

Question 17

X-ray crystallography revealed several important features of the shape of DNA. Which one of the following facts about DNA was NOT revealed by X-ray crystallography?

A) The shape of the molecule is helical.
B) The amount of purine bases equals the amount of pyrimidine bases.
C) The molecule has a constant diameter.
D) The phosphate groups are located on the outside.
E) All of these were revealed by X-ray crystallography.

Question 18

The disease SARS is spread by ______.

A) skin to skin contact
B) sexual intercourse
C) blood infections
D) sneeze droplets
E) more than one of these

Question 19

The study of which of the following diseases led to the discovery that DNA carries genetic information?

A) Pneumonia
B) AIDS
C) Tuberculosis
D) Spanish flu
E) SARS

Question 20

In human cells, DNA replication begins at the top of each chromosome and spreads down the length.

Question 21

The sugar found in DNA is a ____________________.

Question 22

If one side of a small DNA molecule has the nucleotide sequence 5'-AATCGC-3', the opposite side sequence would read (left-to-right) ____________________.

Question 23

____________________ proteins function in the packaging of DNA in the chromosome.

Question 24

In humans, ____________________ functions to transfer genetic information from the nucleus to the cytoplasm.

Question 25

The type of chemical bond that connects the sugars and phosphates together in a DNA molecule is a _______________ bond.

Question 26

Replication in human cells begins at sites called ____________________, present along the chromosome.

Question 27

A DNA molecule has four "ends"- two on each of the two polynucleotide strands. How many of these ends are phosphate groups?

Question 28

The two strands of each polynucleotide chain in DNA are identical.

Question 29

Which of the three parts of a nucleotide (nitrogen base, phosphate, sugar) lies between the other two? ____________________

Question 30

In the structure of DNA, the total amount of ____________________ and ____________________ equals the total amount of ____________________ and ____________________.

Question 31

The nitrogenous bases of DNA stores genetic information.

Question 32

A ____________________ is made up of a sugar, a phosphate, and a nitrogenous base.

Question 33

The name of the enzyme that replicates DNA is ____________________.

Question 34

DNA replication occurs during cytokinesis.

Question 35

DNA is made up of a linear array of ____________________.

Question 36

The base found in DNA, but not RNA, is ____________________; the base found in RNA, but not DNA, is ____________________.

Question 37

If a DNA molecule was a ladder, the rungs of the ladder would be formed by the ____________ and the rails of the ladder would be formed by the ______________.

Question 38

Cytosine and thymine are the two types of bases found in DNA known as ______________________.

Question 39

The unit structure of chromatin is the ____________________, which is made up of ____________________ types of ____________________ proteins complexed with DNA.

Question 40

After replication of a DNA molecule is completed, two molecules are present: the original DNA and a newly synthesized DNA.

Question 41

DNA is synthesized in a 5' - 3' direction during replication. That is, the 5' end of each new strand is laid down first. Why is it necessary, as DNA unwinds to replicate, to have one strand synthesized continuously and the other synthesized in short fragments that are later linked into long chains?

Question 42

Very rarely, DNA polymerase makes mistakes and during replication inserts a "wrong" (non-complementary) nucleotide into the new DNA strand (e.g., inserts a G opposite a T). What are the consequences of such errors?

Question 43

In bacteria, there is direct evidence that DNA is the carrier of genetic information. What evidence is available to support this conclusion in humans or other higher organisms?

Question 44

A _______________ molecule connects two ribose sugars together in an RNA molecule.

Question 45

The type of chemical bond that holds together adenine and thymine in the middle of a DNA molecule is a ________________ bond.

Question 46

What role might nucleosomes play in chromosome structure? What are the dimensions of the problem in packing a diploid amount of DNA into a typical nucleus?

Question 47

RNA molecules have two definably different ends: a head (the 5') and a tail (the 3'). Do DNA molecules similarly have head and tail ends? Why or why not?

Question 48

Describe the chemical composition and structure of DNA.

Question 49

The woman scientist who made a major contribution to the discovery of the structure of DNA was _____________________.

Question 50

What are the properties of genes that must be accounted for in proposing DNA or any other molecule as a carrier of genetic information?

Question 51

Describe the structure of nucleosomes.

Question 52

Both ________________ and _________________ have a two-ringed chemical structure.