DNA

Question 1

In 1928, Frederick ________ studied a pneumonia-causing bacterium. There were 2 strains, the virulent (__) and the nonvirulent (__) strain.

Answer 1

Griffith, S, R

Question 2

In Griffith’s mice experiment, the __ strain on its own killed mice, the __ strain on its own did not kill the mice. Furthermore, when the __ strain was killed by ________, it did not kill the mice. However, combining the ________-killed virulent (__) strain with the live non-virulent (__) strain killed the mice.

Answer 2

S, R, S, heat, heat, S, R

Question 3

Griffith called the transfer of virulence from the heat-killed S strain cells into the live R strain cells ________

Answer 3

transformation

Question 4

In 1944, Avery, Macleod, and ________ repeated Griffith’s experiment using purified cell extracts. They treated the __ cells, and then mixed with the __ cells to inject the mice. They used two treatments: ________ digesting enzymes and ________ digesting enzymes.

Answer 4

McCarty, S, R, Protein, DNA

Question 5

In the Avery, Macleod, and McCarty experiment, the removal of ________ from the transforming material didn’t inhibit its ability to transform R strain cells. However, the ________ digesting enzymes destroyed all transforming ability.

Answer 5

protein, DNA

Question 6

The Avery, Macleod, McCarty experiment supported ________ as the genetic material (at least in bacteria)

Answer 6

DNA

Question 7

Hershey and Chase (1952) investigated genetic material using ________, viruses that infect bacteria. They are composed of only ________ and ________. Hershey and Chase wanted to determine which molecule is the genetic material that is injected into the bacteria.

Answer 7

Bacteriophages, DNA, protein

Question 8

In the Hershey and Chase experiment, Bacteriophage DNA was labeled with radioactive ________ (___), bacteriophage protein was labeled with radioactive ________ (___).

Answer 8

phosphorus, 32P, sulfur, 35S

Question 9

In the Hershey and Chase experiment, only the bacteriophage ________ (___) entered the bacteria and was used to produce more bacteriophage. The conclusion is that ________ is the genetic material

Answer 9

DNA, 32P, DNA

Question 10

DNA is a ________ acid composed of ________

Answer 10

nucleic, nucleotides

Question 11

DNA is composed of a 5-carbon sugar called ________

Answer 11

deoxyribose

Question 12

DNA has a ________ group attached to the 5- carbon of sugar

Answer 12

Phosphate

Question 13

DNA has a ________ group attached at the 3’ carbon of sugar

Answer 13

hydroxyl

Question 14

A ________ bond is the bond between adjacent nucleotides. It is formed between the (__’) PO4 group of one nucleotide and the (__’) OH group of the next nucleotide.

Answer 14

phosphodiester, 5, 3

Question 15

The chain of nucleotides in DNA has a ___ to ___ orientation

Answer 15

5’, 3’

Question 16

Erwin Chargaff determined that there is always an equal proportion of two-ringed ________ (A and G) and single-ringed ________ (C and T).

Answer 16

purines, pyrimidines

Question 17

According to Chargaff’s rules, the amount of Adenine = ________, and the amount of Cytosine = ________.

Answer 17

thymine, guanine

Question 18

Rosalind Franklin performed X-ray diffraction studies to identify the 3D structure of DNA, and discovered that DNA is ________

Answer 18

helical

Question 19

________ and ________ (1953) determined the structure of DNA using evidence from others. They didn’t perform a single experiment themselves.

Answer 19

Watson, Crick

Question 20

They key finding of the Watson-Crick model of DNA was that there are two intertwined chains of ________, creating a ________-________ structure

Answer 20

nucleotides, double-helix

Question 21

The double helix of DNA forms two grooves: The larger ________ groove and the smaller ________ groove

Answer 21

major, minor

Question 22

DNA strands are connected via ________ bonds between bases on opposite strands. The result is specific ________-________ (A-T and G-C)

Answer 22

hydrogen, base-pairs

Question 23

The pattern of base-pairing is ________. A forms __ hydrogen bonds with T, and G forms __ hydrogen bonds with C.

Answer 23

complementary, 2, 3

Question 24

DNA has an ________ formation, meaning that one end terminates in 3’ OH, and one end terminates in 5’ PO4. Two strands of a single DNA molecule have opposite ________ to one another

Answer 24

antiparallel, polarity

Question 25

The ________ model of DNA replication is where both strands of parental DNA remain intact, and the new DNA copies consist of all new molecules

Answer 25

Conservative

Question 26

The ________ model of DNA replication is where the daughter strands each consist of one parental strand and one new strand.

Answer 26

semiconservative

Question 27

The ________ model of DNA replication is where new DNA is dispersed throughout each strand of both daughter molecules after replication

Answer 27

dispersive

Question 28

Meselson and Stahl performed an experiment with heavy nitrogen (___) and combined it with lighter nitrogen (___). They determined that the ________ model is the correct model of DNA replication

Answer 28

N15, N14, semiconservative

Question 29

DNA replication requires three things: Something to copy (parental ________ molecule), Something to do the copying (________), and building blocks to make the copy (________ ________)

Answer 29

DNA, enzymes, Nucleotide triphosphates

Question 30

The stages of DNA replication are as follows: ________ - replication begins, ________ - new strands of DNA are synthesized by DNA polymerase, and ________ - replication is stopped

Answer 30

Initiation, elongation, termination

Question 31

DNA ________ match existing DNA bases with complementary ________ and link them, building new DNA strands

Answer 31

polymerases, nucleotides

Question 32

DNA polymerases all add new bases to the ___ end of existing strands, and synthesize the new strand in the ___ to ___ direction. They also require an ________ primer

Answer 32

3', 5', 3', RNA

Question 33

In Prokaryotic Replication (in E. Coli), there is a single ________ molecule of DNA. Replication begins at the ________ of replication, and proceeds in both directions around the ________.

Answer 33

circular, origin, chromosome

Question 34

A ________ is DNA controlled by an origin

Answer 34

Replicon

Question 35

E. Coli has three DNA polymerases, which all have 3' to 5' exonuclease activity ( ________)

Answer 35

proofreading

Question 36

In prokaryotic replication, DNA polymerase ___ acts on the lagging strand to remove primers and replace them with DNA

Answer 36

I

Question 37

In prokaryotic replication, DNA polymerase ___ is involved in DNA repair processes

Answer 37

II

Question 38

In prokaryotic replication, DNA polymerase ___ is the main replication enzyme

Answer 38

III

Question 39

In prokaryotic replication, ________ unwinds ________ bonds holding them together

Answer 39

helicase, hydrogen

Question 40

In prokaryotic replication, ________ ________ ________ replicated DNA molecules to build a new strand of DNA

Answer 40

DNA Polymerase III

Question 41

In prokaryotic replication, ________ makes the RNA primer so that DNA Polymerase ___ can know where to start.

Answer 41

Primase, III

Question 42

In prokaryotic replication, ________ essentially glues DNA fragments together on the ________ strand.

Answer 42

ligase, lagging

Question 43

Some DNA polymerase molecules can remove nucleotides, acting as ________. They can be ________ (cut DNA internally) or ________ (remove nucleotides from end of DNA).

Answer 43

nucleases, endonucleases, exonucleases

Question 44

Helicases use energy from ________ to unwind DNA

Answer 44

ATP

Question 45

________-________-________ proteins coat strands of DNA to keep them apart after helicase separates them.

Answer 45

Single-strand-binding

Question 46

Unwinding of DNA by helicase causes torsional strain that can lead to additional twisting of the helix, called ________.

Answer 46

supercoiling

Question 47

The enzymes that prevent supercoiling are called ________. The specific one involved in DNA replication is called DNA ________

Answer 47

Topoisomerases, gyrase

Question 48

DNA fragments on the lagging strand are called ________ ________, and must be connected together.

Answer 48

Okazaki fragments

Question 49

The ________ ________ is a partial opening of helix formed where double stranded DNA is being unwound. This is where DNA ________ occurs.

Answer 49

replication fork, synthesis

Question 50

________ is the ability of a polymerase to stay attached

Answer 50

Processivity

Question 51

The β subunit forms a "sliding clamp" to keep DNA Polymerase ___ attached to DNA (high processivity)

Answer 51

III

Question 52

A ________ is a macromolecular assembly of enzymes involved in DNA replication. The two main components are ________ (primase, helicase, accessory proteins) and the ________ of two DNA Pol III's (one for each strand)

Answer 52

Replisome, primosome, complex

Question 53

Eukaryotic replication is more complex than prokaryotes due primarily to larger amounts of ________ in multiple ________, and a ________ structure (vs. circular chromosomes)

Answer 53

DNA, chromosomes, linear

Question 54

In Eukaryotic replication, multiple ________ (origins of replication) are used for each chromosome

Answer 54

replicons

Question 55

Before S phase in eukaryotes, ________ are loaded onto possible replication origins, but not activated

Answer 55

helicases

Question 56

In Eukaryotic replication, priming uses a complex of both DNA polymerase ___ and ________.

Answer 56

α, primase

Question 57

DNA polymerase ________ synthesizes the leading strand in Eukaryotic replication

Answer 57

epsilon (ε)

Question 58

DNA polymerase ________ synthesizes the lagging strand in Eukaryotic replication

Answer 58

delta (δ)

Question 59

Linear chromosomes (eukaryotic) have specialized structures found on the ends of eukaryotic chromosomes called ________. They are composed of specific ________ sequences

Answer 59

Telomeres, repeat

Question 60

Telomeres protect the ends of chromosomes from ________. They are also not made by the ________ complex.

Answer 60

nucleases, replication

Question 61

The last primer removed from the 3' end of the lagging strand in eukaryotes cannot be replaced, and this would result in the ________ of chromosomes with each round of cell division. So, the enzyme ________ synthesizes the ________ repeat sequences at the end of the strand. This enzyme uses an internal ________ template, not the DNA itself

Answer 61

shortening, telomerase, telomere, RNA

Question 62

Telomerase is ________ regulated. It is high in ________, and low in ________.

Answer 62

developmentally, childhood, adulthood

Question 63

DNA damage constantly occurs. There can be random errors during ________. Luckily, DNA polymerases have ________ ability to counteract this.

Answer 63

replication, proofreading

Question 64

________ are any agent that increases the number of mutations above background level. Examples are radiation and chemicals

Answer 64

Mutagens

Question 65

There are two categories of DNA repair: ________ repair and ________ repair. The first targets a single kind of lesion in DNA and repairs only that damage. The 2nd uses a single mechanisms to repair multiple kinds of lesions in DNA.

Answer 65

specific, nonspecific

Question 66

A ________ ________ removes incorrect bases incorporated during DNA replication. It replaces them with the correct base by copying the ________ strand.

Answer 66

Mismatch repair (MMR), template

Question 67

________ is a specific repair mechanism that repairs damage caused by exposure to UV light. The ________ enzyme absorbs light in the visible range and uses the energy to ________ thymine dimers.

Answer 67

Photorepair, photolyase, cleave

Question 68

________ repair is a nonspecific repair that removes and replaces a damaged region of DNA by DNA ________ using ________ ________.

Answer 68

Excision, synthesis, DNA Polymerase