Ap Biology Chapter 16 Test

Front 1

Who did the following? He worked with two strains of S. pneumoniae. When he mixed the remains of heat-killed pathogenic bacteria with harmless bacteria, some bacteria were changed into disease-causing bacteria. These bacteria had incorporated external genetic material in the process of transformation, which results in the change in genotype and phenotype.

Back 1

F. Griffith

Front 2

Who worked for more than a decade to identify the transforming agent by purifying chemicals from heat-killed pathogenic cells?

Back 2

O. Avery

Front 3

Which three men announced that DNA was the genetic material?

Back 3

Avery, McCarty, and MacLeod

Front 4

bacteriophages, or phages

Back 4

they are viruses that infect bacteria

Front 5

Which two men showed that DNA was the genetic material of a phage known as T2 that infects the bacterium E. coli?

Back 5

Hershey and Chase

Front 6

Who reported that the ratio of nitrogenous bases in the DNA from various organisms was species specific and determined that the number or as and ts was approximately equal, and the number of gs and cs was also equal in the dna from all the organisms he studied.

Back 6

Chargaff

Front 7

Adenine and Guanine are purines or pyrimidines?

Back 7

adenine and guanine are purines

Front 8

cytosine and thymine are purines or pyrimidines?

Back 8

cytosine and thymine are pyrimidines

Front 9

semiconservative model of dna replication

Back 9

predicts that two daughter dna molecules each have one parental strand and one newly formed strand

Front 10

conservative model of dna replication

Back 10

predicts that the parent double helix reforms and the duplicated molecule is totally new

Front 11

dispersive model of dna replication

Back 11

all four strands of the two dna molecules are a mixture of parental and new dna.

Front 12

Who did the tests with nitrogen to confirm the semiconservative model of dna

Back 12

meselson and stahl

Front 13

where does replication begin?

Back 13

at the origin of replication

Front 14

Where do proteins that initiate replication bind to a specific sequence of nucleotides and separate the two strands to form a replication bubble.

Back 14

the origin of replication.

Front 15

what are replication forks

Back 15

replication forks are the y-shaped things in which the direction of replication occurs

Front 16

What do dna polymerases do?

Back 16

dna polymerases are enzymes that connect nucleotides to the growing end of the new dna strand.

Front 17

what provides the energy for replication to occur?

Back 17

a nucleoside triphosphate loses two phosphate groups and the hydrolysis of the two inorganic phosphates provides the energy for polymerization

Front 18

_______________ add nucleotides only to the 3 prime end of growing strands

Back 18

dna polymerase

Front 19

DNA is replicated in what direction?

Back 19

five prime to three prime

Front 20

What is the leading strand?

Back 20

the leading strand is the new five prime to three prime strand being formed along the template by dna polymerase III in the progressing replication fork

Front 21

what forms the leading strand along the template in the progressing replication fork?

Back 21

dna polymerase iii

Front 22

What is the lagging strand?

Back 22

the lagging strand is created as a series of short segments (okazaki frangments) that are formed in the five prime to three prime direction away from the replication fork.

Front 23

what are okazaki fragments

Back 23

they are short segments that are formed on the lagging strand in the five prime to three prime direction away from the replication fork.

Front 24

what is dna ligase

Back 24

dna ligase joins the sugar phosphate backbones of the fragments

Front 25

what is the role of primase

Back 25

primase joins about 10 rna nucleotides to form the primer which is needed to start the chain.

Front 26

what is primer

Back 26

the primer is needed to start the dna replication synthesis of a dna strand.. it is the series of ten rna nucleotides... each fragment on the lagging strand requires a primer.

Front 27

what does dna polymerase 1 do?

Back 27

dna pol 1 replaces the rna primer with dna nucleotides

Front 28

helicase

Back 28

unwinds the helix and separates the parent strand at replication forks

Front 29

single-strand binding proteins

Back 29

keep the separated strands apart while they serve as templates.

Front 30

topoisomerase

Back 30

helps relieve the strain from the twisting of dna strands in front of helicase

Front 31

what is a mismatch pair

Back 31

a mismatch pair is an incorrectly paired nucleotide

Front 32

what is nucleotide excision repair

Back 32

nucleotide excision repair is the damaged strand is cut out by a nuclease and the gap is correctly filled through the action of dna polymerase and ligase

Front 33

what is a nuclease

Back 33

an enzyme which cuts out a damaged strand of dna

Front 34

what do telomeres do?

Back 34

telomeres are short nucleotide sequences at the end of chromosomes which protect an organism's genes from being shortened during successive dna replications

Front 35

what is telomerase

Back 35

telomerase is the enzyme which contains an rna template for the telomere sequences, and lengthens telomeres.

Front 36

one of the reasons most scientists believed proteins were the carriers of genetic info was that
a.proteins were more heat stable than nucleic acids
b.the protein content of duplicating cells always doubled prior to division
c.proteins were much more complex and heterogeneous molecules than nucleic acids
d.early experimental evidence pointed to proteins as the hereditary material
e.proteins were found in DNA

Back 36

c. proteins were much more complex and heterogeneous molecules than nucleic acids

Front 37

transformation involves...
a.the uptake of extermal genetic material, often from one bacterial strain to another.
b.the creation of a strand of rna from a dna molecule
c.the infection of bacterial cells by phage
d.the type of semiconservative replication shown by DNA
e.the replication of dna along the lagging strand

Back 37

a. the uptake of external genetic material, often from one bacterial strain to another.

Front 38

the dna of an organism has thymine as twenty percent of its bases. what percentage of its bases would be guanine?
a.20
b.30
c.40
d.60
e.80

Back 38

b.30

Front 39

in his work with pneumonia-causing bacteria, Griffith found that ...
a.dna was the transforming agent
b.the pathogenic and harmless strains mated.
c.heat-killed harmless cells could cause pneumonia when mixed with heat-killed pathogenic cells
d.some heat-stable chemical was transferred to harmless cells to transform them into pahtogenic cells.
e.a T2 phage transformed harmless cells to pathogenic cells

Back 39

d.some heat-stable chemical was transferred to harmless cells to tranform them into pathogenic cells

Front 40

when t2 phages are grown with radioactive sulfur...
a.their dna is tagged.
b.their proteins are tagged
c.their dna is found to be of medium density in a centrifuge tube
d.they transfer their radioactivity to E. coli chromosomes when they infect the bacteria.
e.their excision enzymes repair the damage caused by the radiation.

Back 40

b. their proteins are tagged

Front 41

meselson and stahl...
a.provided evidence for the semiconservative model of dna replication
b.were able to separate phage protein coats from e. coli by using a blender
c.found that dna labeled with 15N was of intermediate density
d.grew e. coli on labeled phosphorus and sulfur.
e.found that dna composition was species specific

Back 41

a. provided evidence for the semiconservative model of dna replication.

Front 42

watson and crick concluded that each base could not pair with itself because...
a. there would not be room for the helix to make a full turn every 3.4 nm
b.the uniform width of 2 nm would not permit two purines or two pyrimidines to pair together.
c.the bases could not be stacked .34 nm apart.
d. identical bases could not hydrogen bond together
e.they would be on antiparallel strands

Back 42

b. the uniform width of 2 nm would not permit two purines or two pyrimidines to pair together.

Front 43

the joining of nucleotides in the polymerization of dna requires energy from
a.dna polymerase
b.the hydrolysis of the terminal phosphate group of atp
c.rna nucleotides
d.the hydrolysis of gtp
e.the hydrolysis of the pyrophosphates removed from nucleoside triphosphates

Back 43

e. the hydrolysis of the pyrophosphates removed from nucleoside triphosphates

Front 44

continuous elongation of a new dna strand along one strand of dna
a.requires the action of dna ligase as well as polymerase
b.occurs because dna ligase can only elongate in the five prime to three prime direction
c.occurs on the leading strand
d.occurs on the lagging strand.
e.a, b, and c are correct

Back 44

c. occurs on the leading strand

Front 45

which of the following statements about dna polymerase is incorrect
a.it forms the bonds between complementary base pairs
b.it is able to proofread and correct for errors in base pairing
c. it is unable to initiate synthesis; it requires an rna primer
d.it only works in the five prime to three prime direction
e.it is found in eu and prokaryotes

Back 45

a. it forms the bonds between complementary base pairs

Front 46

thymine dimers-covalent links between adjacent thymine bases in dna-may be induced by uv light. when they occur, they are repaired by....
a. excision enzymes (nucleases)
b.dna polymerase
c.ligase
d.primase
e.a,b, and c are all needed

Back 46

e. all are needed

Front 47

how does dna synthesis along the lagging strand differ from that on the leading strand?
a.nucleotides are added to the five prime end instead of the three prime end
b.ligase is the enzyme that polymerizes dna on the lagging strand
c.okazaki fragments, which each grow five to three prime must be joined along the lagging strand.
d.okazaki fragments, which each grow from five to three prime must be joined along the lagging strand.
e. helicase synthesizes okazaki fragments, which are then joined by ligase.

Back 47

d. okazaki fragments, which each grow from five to three prime, must be joined along the lagging strand

Front 48

which of the following enzymes or proteins is paired with an incorrect or inaccurate function?
a.helicase-unwind and separate parental double helix
b.telomerase-add telomere repetitions to end of chromosomes
c.single-strand binding protein-hold strands of unwound dna apart and straight
d. nuclease-cut out damaged dna strand
e.primase-form dna primer to start replication

Back 48

e.primase-form dna primer to start replication

Front 49

t2 phage is grown in e coli with radioactive phosphorus and then allowed to infect other e coli. the culture is blended to separate the viral coats from the bacterial cells and centrifuged. which of the following best describes the expected results of such an experiment?
a.both viral and bacterial dna are labeled; radioactivity is found in the supernatant
b.both viral and bacterial proteins are labeled; radioactivity is present in both the supernatant and the pellet.
c.viral proteins are labeled; radioactivity is found in the supernatant but not in the pellet
d.viral dna is labeled; radioactivity is found in the pellet
e.the virus destroyed the bacteria; no pellet is formed.

Back 49

d. viral dna is labeled; radioactivity is found in the pellet

Front 50

what are telomeres, and what do they do?
a. evershortening tips of chromosomes that may signal cells to stop dividing at maturity
b. highly repetitive sequences at tips of chromosomes that protect the lagging strand during replication
c.repetitive sequences of nucleotides at the centromere region of a chromosome
d.enzymes that are present in germ0line cells that allow these cells to undergo repeated divisions
e. both a and b are correct

Back 50

e. both a and b

Front 51

you are trying to support your hypothesis that dna replication is conservative; i.e. parental strands separate; complementary stransds are made, but these new strands join together to make a new dna molecule, and the parent al strands join. you take e coli that had grown in a meduim containing only heavy nitrogen (15N) and transfer a sample to a medium containing light nitrogen (14 N). After allowing time for only one DNA replication, you centrifuge a sample and compare the density band(s) formed with control bands for bacteria grown on either normal 14 N or 15 N medium. Which band location would support your hypothesis of conservative DNA replication?... using the experiment explained above, which centrifuge tube would represent the band distribution obtained after one replication showing that dna replication is semiconservative?

Back 51

a tube with a band at the top and at the bottom... the same as the control tube.

semiconservative would look like a single bar in between the two distances of the two in the control tube.

Front 52

what is transformation?

Back 52

transformation changes genotype and phenotype