BIO chapter 9

___and___ performed an experiment that demonstrated the semiconservative mechanism of DNA replication

Meselson and Stahl

Who is credited with the discovery of DNA

Miescher

DNA polymerase synthesizes short fragments of DNA on the lagging strand during DNA replication. These are called what

Okazaki fragments

The researcher who identified that regions of proteins can fold into an alpha helix was

Pauling

Which could possibly have contaminated the cell extract obtained by Avery, MacLeod, and McCarty in their famous experiments

Protein and RNA

What can serve as the genetic material in viruses

RNA or DNA

Of the following choices, which are base paired properly

A-T C-G

Why did the injection of dead smooth bacteria not kill Griffith's mice

Because dead bacteria are unable to cause disease

By about how many times does the 30-nm fiber shorten the nucleosome structure

Seven

In Escherichia call, what enzyme adds DNA nucleotides during DNA replication

DNA polymerase III

DNA replication proceeds outward from two___ , which are the sites where the template strands are unwound and new DNA is synthesized

replication forks

The presence of the sugar___ would definitively identify a nucleic acid as RNA

ribose

The proposed models for DNA replication included

semiconservative replication dispersive replication conservative replication

The nucleosome fiber shortens the length of the DNA molecule about

sevenfold

The length of a metaphase chromosome is___ a chromosome in a non-dividing cell

shorter than

prevents the two DNA template strands from re-forming the double helix

single-strand binding protein

The function of ___ is to coat the single strands of template DNA to prevent them from re-forming a double helix

single-strand binding proteins

Directionally refers to the orientation of

sugar molecules in a DNA strand

The components of a nucleotide are

sugar, phosphate, base

The DNA backbone is composed of alternating

sugars and phosphate groups

The prime symbol is used to distinguish carbons in

sugars from carbons in nitrogenous bases

The DNA strands that can be copied to produce new DNA strands are called the

template strands

In DNA replication the strands on the original molecule are used as___ for the synthesis of new DNA strands

templates

A single turn of the double helix consists of___ base pairs

ten

Griffth's experiments were important because they showed

that the genetic material could be passed form one cell to another

Erwin Chargaff showed that

the amounts of A/T and C/G are equal

replication

the substance that produces the capsule or not

Information

the transformed cells pick up material from dead cells

transmission

the transforming principle is passed via binary fission

Assuming DNA replication had been conservative, Meselson and Stahl would have observed what bands in the centrifuge tube after one round of replication

Two bands: one heavy and one light

In the Avery, McLeod and McCarty experiment, which of the following mixtures would yield smooth colonies when plated

Type R bacteria + type S DNA extract + RNase Type R bacteria + type S DNA extract + protease Type R bacteria + type S DNA extract

___ and ___ proposed that the structure of DNA was a double helix

Watson and Crick

Which of the following helps explain the remarkably high fidelity for DNA replication

The hydrogen bonding between AT and CG pairs is more stable than between mismatched pairs DNA polymerase can identify and repair mismatched nucleotides DNA polymerase is unlikely to catalyze bond formation between adjacent nucleotides if a mismatched base pair is formed

Rosalind Franklin, a British biophysicst, analyzed DNA using___techniques, and proposed that the molecule had a helical structure with a uniform diameter

X-ray diffraction

The major groove of the DNA double helix.

a binding site for proteins that control gene expression

In a DNA chain, adjacent nucleotides are linked via a bond between

a sugar molecule in one and a phosphate group in the other

Which bases are connected by two hydrogen bonds

adenine and thymine

DNA replication relies on the___ of DNA strands according to the___ rule

complementarity;AT/GC

A strand of DNA or RNA is composed of a linear array of nucleotides held together by___ bonds

covalent

During DNA replication, the two original strands of DNA are used to synthesize two

daughter strands

As DNA polymerase slides along the DNA, individual nucleotides with three phosphate groups, called___ , hydrogen-bond to the exposed bases in the___ strand according to the AT/GC rule

deoxynucleoside triphosphates;template

The___ model suggest that DNA replication produces DNA strands in which segments of new DNA are interspersed with the parental DNA

dispersive

The level of DNA structure that resembles a spiral staircase in the

double helix

Purine bases have a___-ring structure and include adenine and____. On the other hand, pyrimidines have a___-ring structure and include cytosine, thymine, and___

double; guanine single;uracil

A nucleosome consists of a core of

eight histone proteins: two each of H2A, H2B, H3 and H4

The less condensed regions of chromosomes are referred to as

euchromatin

The term___ is used to describe the less condensed regions of eukaryotic chromosomes

euchromatin

The term high___ refers to a process that occurs with relatively few mistakes

fidelity

DNA must be compacted in order to

fit in cells

At the replication fork, the enzyme DNA helicase binds to one DNA strand and travels in this direction using energy from ATP

from 5' to 3'

The complete complement of an organism's genetic material is called the

genome

Select all of the following that are purine bases

guanine and adenine

DNA replication of the prokaryotic chromosome

has a single origin of replication and is bidirectional

The enzyme DNA___ separates the DNA strands and keeps the replication fork moving forward

helicase

causes DNA strand separation at the origin of replication

helicase

The term___ is used to describe the highly compacted regions of eukaryotic chromosomes

heterochromatin

___ are a group of proteins that DNA wraps around to compact itself and to form nucleosomes

histones

DNA and RNA are called nucleic acids because they release___ ions in solution and have a net___ charge at neutral pH

hydrogen;negative

X-ray___ patterns are mathematically related to the structural arrangement of atoms causing a scattering pattern, which can be used to explain the three dimensional structure of molecules

diffraction

The orientation of sugar molecules within a DNA strand is referred to as___ . For example, a strand is said to be 5' to 3' or 3' to 5'

directionality

In order for the genetic material to fullfill its role in cells, it must meet which of the following criteria

information replication transmission variation

In DNA replication, the___ strand is made discontinuously in the direction opposite to the movement of the replication fork

lagging

Relative to prokaryotic chromosomes, eukaryotic chromosomees are

larger

During DNA replication, the___ strand is synthesized continuously while the___ strand is synthesized as small fragments that are connected to each other to form a continuous strand

leading;lagging

Nucleosomes are connected by___ regions of DNA that vary in length from 20 to 100 base pairs depending on species and cell type

linking

Injection of which of the following in Griffith's experiments would cause the death of mice

live smooth bacteria + live rough bacteria dead smooth bacteria + live rough bacteria live smooth bacteria

The DNA double helix consists of the___ groove and the___ groove

major and minor

The nuclear___ consists of the nuclear lamina made of protein fibers and other proteins that are connected to the lamina and fill the interior of the nucleus

matrix

During DNA replication in bacteria, only 1 mistake is made per 100___ nucleotides

million

In eukaryotes, the DNA is found in the nucleus,___ and___

mitochondria and chloroplast

Meselson and Stahl used two isotopes of the element___ in their DNA replications experiments, so that the daughter strands could be distinguished from the parental strands

nitrogen

The 30-nm fiber is comprised of___ units organized into a more compact structure

nucleosome

The repeating structural unit of eukaryotic chromatin is the___

nucleosome

DNA is a macromolecule composed of monomers called___

nucleotides

According to the conservative model, DNA replication produces

one molecule with two parental strands and another molecule with two daughter strands.

DNA template strands are referred to as___ strands, while the newly synthesized strands are referred to as___ strands

parental;daughter

The negative charges found in the___ groups of DNA are attracted to the positives charges on___ proteins found in chromatin

phosphate;histone

The 5' end of a DNA strand has a___ group, and the 3' end has a___ group

phosphate;hydroxyl

In a DNA strand, adjacent nucleotides are held together by covalent bonds known as___ bonds

phosphoester

The bacterium Streptococcus pneumoniae causes the disease___ , which can be fatal

pneumonia

The enzyme DNA___ covalently links nucleotides to synthesize new DNA strands together during DNA replication

polymerase

The enzyme works by breaking a bond between the first and second phosphate and attaching a nucleotide dNMP to the 3' end of the DNA strand via a phosphodiester

polymerase

Histone proteins contain a large number of___ amino acids that can bind to the___

positively-charged; negative charges on the phosphates of DNA

Rank the five levels of structural features of DNA. Start at the top with the most complex

1. genome 2. chromosome 3. double helix 4. DNA strand 5. nucleotide

In order to complete synthesis of the Okazaki fragments on the lagging strand, the following must occur

1. the removal of RNA primers 2. the synthesis of DNA in the area where the primers have been removed 3. the covalent joining of adjacent fragments of DNA

Place the steps of eukaryotic chromosomal compaction leading to the metaphase chromosome in the correct order

1. wrapping of DNA around histones 2. formation of a 30-nm fiber via histone H1 and other DNA binding proteins 3. anchoring of radial loop domains to the nuclear matrix 4. further compaction of radial loops to form heterochromatin

During proofreading, DNA polymerase removes the incorrect base in the___ direction, and then adds the correct base in the___ direction

3' to 5'; 5' to 3

A segment of DNA has the sequence 5'-ATGCTT-3'. The complementary sequence would be

3'-TACGAA-5'

A double-stranded DNA molecule contains 20% thymine. The molecule would have to contain___% guanine

30

The compaction of DNA involves interactions between which two of the following

30 nm fibers and nuclear matrix

A human somatic cell contains___ chromosomes

46

DNA helicase travels toward the replication fork using energy form ATP in this direction

5' to 3'

Heterochromatin regions of the chromosome tend to have a diameter of about___ while, euchromatic regions have an average width of about___

700 nm; 300 nm

If a strand of DNA has a T nucleotide, the complementary strand will have which nucleotide paired with the T

A

Avery, McLeod, and McCarty used established biochemical procedures to purify marcomolecules from the type S streptocci. They found out that R bacteria can only be transformed by what type of purified macromolecule

DNA

___ synthesis begins a a site within a chromosome called the origin of replication

DNA

The Avery, MacLeod, and McCarty experiments involved mixing substances with rough bacterial cells.

DNA + RNase DNA + DNase DNA DNA + protease

Which of the following are nucleic acids

DNA and RNA

A chromosome is composed of

DNA and proteins

Chromatin makes up eukaryotic chromosomes and is a complex of

DNA and proteins

Avery, McLeod, and McCarty demonstrated that only purified

DNA can convert type R bacteria into type S

Which of the following processes proceeds according to the AT/GC rule

DNA replication

Of the following structural features of DNA, which comprises all the others

Genome

A process that occurs with relatively few mistakes is described by what terminology

High fidelity

Which of the following are enzymatic features of DNA polymerase

It can only synthesize DNA in the 5' to 3' direction It is unable to begin DNA synthesis on a bare template strand

Which enzyme catalyzes the formation of covalent bonds between adjacent DNA fragments to complete the replication process

Ligase

Which of the following are properties of the DNA double helix proposed by Watson and Crick

The DNA strands are antiparallel The DNA strands obey the AT/GC rule

Which of the following is found in DNA and not in RNA

Thymine

In a DNA double helix, one strand runs 5' to 3' in one direction, while the other goes 3' to 5' in the same direction. This characteristic describes the___ nature of the two strands

antiparallel

Two DNA strands in a double helix that run in opposite directions from one another are said to be___

antiparallel

The genome of a bacterial cell is different from that of a eukaryotic cell because the bacterial genome exists

as a single circular chromosomes

variation

bacteria have the ability to produce a capsule or not

The covalent linkage of a sequence of___ allows DNA to store information

bases

The most current model of chromatin structure suggests that the linker regions in the 30 nm structures are

bent and twisted with little direct contact between nucleosomes

DNA replication is described as___ because DNA replication proceeds outward from two replication forks

bidirectional

The function of single-strand___ proteins is to coat the single strands of template DNA to prevent them from re-forming a double helix

binding

Griffith's experiment demonstrated that the formation of the___ to produce smooth(S) bacteria is governed by genetic material

capsule

The appearance of colonies of Streptoccus pneumoniae is related to the presence or absence of

capsule

The difference between euchromatin and heterochromation relates to the

compaction level of the molecule

The enzyme DNA___ is needed to begin DNA synthesis on a bare template strand. This enzyme makes a short segment of___ RNA called a primer that is complementary to a DNA sequence on the template strand

primase;RNA

In compaction of chromatin, the___ domains are often 25,000 to 200,000 base pairs in size

radial loop

A third level of compaction of eukaryotic chromosomes involves the formation of___ domains in which the 30-nm fibers are anchored to the nuclear matrix to form___

radial loop; euchromatin

DNA polymerase I___ RNA primers in the___ direction

removes; 5' to 3'

Guanine forms ___ hydrogen bonds with cytosine.

three

Guanine forms___ hydrogen bonds with cytosine

three

Relieves coiling in DNA strands ahead of the replication fork

topoisomerase

The enzyme DNA___ relieves coiling in DNA strands ahead of the replication fork

topoisomerase

The semiconservative mechanism of DNA replication produces

two molecules each with a parental strand and a daughter strand

Which of the following are pyrimidine bases

uracil, cytosine, thymine

Watson and Crick deduced the structure of DNA by

using a ball-and-stick model