bio ch 12

DNA synthesis proceeds from _______ direction.

5'-3'

match: demonstrated that genetic traits can be transferred from one bacterium to another

griffith

. The bacteriophages used in Alfred Hershey's and Martha Chase's experiments showed that:

DNA was injected into bacteria.

Antiparallel=

Said of a double-stranded nucleic acid in which the 5' to 3' direction of the sugar- phosphate backbone of one strand is reversed in the other strand.

DNA replication=

Sequence of nucleotides in DNA are precisely copied and the process

Leading strand =

Strand of DNA that is synthesized continuously

____, the ends of eukaryotic chromosomes, shorten with every cell division.

Telomeres

How is a bacterial chromosome replicated?

The circular DNA molecule is replicated from one origin of replication bidirectionally.

Because a newly synthesized DNA molecule contains ____, the replication process is said to be semiconservative.

one parental strand and one new strand

Match: prevents the hydrolysis of single DNA strands by nucleases

single- strand binding protein

Match: prevents formation of hydrogen bonds between complementary base pairs

single-strand binding protein

Mismatch repair=

special enzyme recognizes the incorrectly paired nucleotides and remove them, DNA polymerase then fill in the missing nucleotides

The ends of eukaryotic chromosomes can be lengthened by:

telomerase.

In replication of DNA is considered semiconservative because each old strand serves as a __________ for the formation of a new strand.

template

From the DNA X-ray crystallography data, Franklin and Wilkins inferred that ____ while Watson and Crick determined that ____.

the flat nucleotide bases are stacked upon each other; DNA is helical.

Chargaff's rules=

the ratio of adenine to thymine and guanine to cytosine was always the same

Errors in DNA replication can come from:

the sun's UV radiation.

Match: produces breaks in the DNA molecules and then rejoins the strands to prevent supercoiling

topoisomerase

True or False: Adenine and thymine are held together by "two" hydrogen bonds in a double-stranded DNA molecule.

true

In the experiments of Griffith, the conversion of nonlethal R-strain bacteria to lethal S-strain bacteria:

was due to transformation.

A replication fork is:

a Y-shaped structure where parental DNA strands are separated by helicase.

Which of the following nucleotide sequences represents the complement to the DNA strand5′ − AGATCCG- 3′?

3′ − TCTAGGC- 5′

What type of subunits make up a single strand of DNA? What do they contain? How are the subunits linked?

Adenine, thymine, guanine, and cytosine nucleotides make up a single strand of DNA. They are linked together through their 5′ phosphate groups that are covalently bonded to the 3′ carbon of the deoxyribose subunit of the next base in the polynucleotide chain

_____ bonds link the sugar and phosphate groups in the backbones of DNA molecules.

Covalent phosphodiester

Match: joins successive nucleotides to a growing polynucleotide strand, complementary to the template strand

DNA polymerase

When a mutation occurs during DNA replication, ____ replaces the incorrect nucleotide with the correct one after the mismatched nucleotide has been removed.

DNA polymerase

true or false: One of the "pyrimidine" bases in a DNA molecule is adenine.

False- Purine

Match: grew bacteria in the presence of heavy nitrogen (15N), followed by growth 14N medium for one or two generations, then measured the density of the DNA

Messelson and Stahl

Give names of three enzymes involved in nucleotide excision repair.

Nuclease, DNA polymerase, and DNA ligase

How are eukaryotic chromosomes replicated?

The linear DNA molecules are replicated from multiple origins of replication bidirectionally.

14. Which of the following statements is FALSE with regard to DNA replication?

The strand being copied is read in the 5'->3' direction.

Which of the following statements concerning DNA is FALSE?

The sugar present in DNA is ribose.

Telomeres=

chromosomes have protective end caps

What allows each strand of DNA to serve as a template for a new DNA strand during replication?

complementary base pairing between purines and pyrimidines on opposite strands

Semiconservative replication=

explains the perpetuation of mutation. Each daughter double helix consists of, 1 original strand from parent molecule and 1 new complementary strand.

In DNA replication, the lagging strand:

is synthesized as a series of Okazaki fragments.

The DNA strand that is replicated smoothly and continuously is called the:

leading strand.

The chemical group in box 5 of the accompanying figure is a:

phosphate

Telomeres shorten slightly with each cell cycle but can be extended by the enzyme ____________.

telomerase

According to Chargaff's rules:

the adenine content in any DNA molecule is always equal to the thymine content.

The bases of nucleotides include 2 purines__________ and 2 pyrimidines ____________.

(adenine (A) or guanine (G)), (thymine (T) or cytosine (C))

Why is DNA able to store large amounts of information?

Its nucleotides can be arranged in a large number of possible sequences.

Match: demonstrated that DNA is replicated semiconservatively

Meselson and Stahl

________ hydrogen bonds form between adenine and thymine, and _______ hydrogen bonds form between guanine and cytosine.

2, 3

Which of the following causes the unwinding of the DNA double helix?

DNA helicase

true or false: The two strands of a DNA double helix can be described as running "parallel" to each other.

False - antiparallel

True or false: The process of DNA replication is "conservative."

False -semiconservative

True or false: An RNA primer is synthesized by "RNA primase"

False- DNA primase

Name 4 nitrogenous bases. (2 purines and 2pyrimidines)

Purines- adenine (A), guanine (G) Pyrimidines- thymine (T), cytosine (C)

Before the 1940s, scientists believed that proteins, rather than DNA, were the carriers of genetic material in the cell. Why?

Twenty different amino acids could produce a large number of unique combinations.

Watson and Crick model suggested that DNA is made up of ___________ to form double helix.

2 nucleotide chains

Origin of replication=

A specific site on the DNA where replication begins

Lagging strand=

A strand of DNA that is synthesized as a series of short segments

Which base connects to which, and how many hydrogen bonds are between them?

A-T, 2 hydrogen bonds C-G, 3 hydrogen bonds

Match: discovered that DNA was responsible for bacterial transformation

Avery

Match: demonstrated the ratio of nucleotide bases in DNA

Chargaff

Match: catalyzes the synthesis of an RNA primer at both leading and lagging strand

DNA helicase

_________ are the enzymes which break hydrogen bond during replication.

DNA helicase

Match: catalyzes a reaction that occurs in the lagging strand but not in the leading strand

DNA ligase

Match: catalyzes formation of sugar-phosphate bonds in adjacent Okazaki fragments

DNA ligase

Okazaki fragments are joined together by:

DNA ligase.

Match: adds nucleotides only to the 3' end of an existing polynucleotide strand

DNA polymerase

Which of the following adds new nucleotides to a growing DNA chain?

DNA polymerase

____________ catalyzes the linking together of nucleotide subunits.

DNA polymerase

True or False: Okazaki fragments are found in the "leading" strand of DNA.

False- Lagging

X-ray diffraction images produced by ____ were used by Watson and Crick to infer the structure of DNA.

Franklin

Match: discovered that the genetic material in bacteriophages is DNA

Hershey and Chase

Match: used proteins labeled with 35S and DNA labeled with 32P to demonstrate that viral DNA entered bacterial cells, but viral proteins did not

Hershey and Chase

Okazaki fragment=

One of many short segments of DNA, each 100 to 1000 nucleotides long, that must be joined by DNA ligase to form the lagging strand in DNA replication.

Double helix=

The structure of DNA, which consists of two antiparallel polynucleotide chains twisted around each other.

Replication fork=

Y-shaped structure produced during the semiconservative replication of DNA.

Mutations=

any change in DNA

Hydrogen bonds can form between guanine and ____, and between adenine and ____.

cytosine; thymine

DNA molecule consists of two polynucleotide chains that associate as a __________.

double helix

Match: binds DNA at the origin of replication and breaks the hydrogen bonds between the paired bases

helicase

Match: opens the double helix like a zipper

helicase

DNA is a nucleic acid which carries the molecular basis of_________

inheritance