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BIOL 3451 - Genetics Lecture > Exam 4 > Flashcards

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1

Three parts of a DNA nucleotide

Phosphate Deoxyribose sugar Nitrogenous base

2

How does an RNA nucleotide differ from a DNA nucleotide?

DNA nucleotides, or deoxyribonucleotides, have a deoxyribose sugar that lacks an oxygen molecule at the 2' carbon of the sugar molecule. Ribonucleotides, or RNA nucleotides, have a ribose sugar with oxygen linked to the 2' carbon of the sugar molecule. Ribonucleotides may contain the nitrogenous base *uracil* but NOT the thymine. DNA nucleotides contain *thymine*, but not uracil.

3

Draw the three parts of a DNA nucleotide.

4

Draw the difference between an RNA nucleotide vs DNA nucleotide.

5

a more stable double-stranded form that stores the genetic blueprint for cells

DNA

6

a more versatile single-stranded form that transfers the genetic information for decoding

RNA

7

two types of nucleic acids present in cells

DNA and RNA

8

Both DNA and RNA are ______ of nucleotides

polymers

9

How does a purine differ from a pyrimidine?

A purine consists of a six-sided ring attached to a five-sided ring.

10

What purines and pyrimidines are found in DNA and RNA? 

In both DNA and RNA, the purines found are adenine and guanine. DNA and RNA differ in the pyrimidine content. The pyrimidine cytosine is found in both RNA and DNA., However, DNA contains the pyrimidine thymine, whereas RNA contains the pyrimidine uracil but not thymine.

11

Draw a purine vs pyrimidine. 

12

Draw a short segment of a single polynucleotide strand, including at least three nucleotides. Indicate the polarity of the strand by identifying the 5' end the 3' end.

13

Which bases are capable of forming hydrogen bonds with each other?

Adenine is capable of forming two hydrogen bonds with thymine. Guanine is capable of forming three hydrogen bonds with cytosine.

14

Name the purines.

Think "GAP". 

Guanine and Adenine are the purines.

15

Name the pyrimidines.

Think "CUT to the rim".

Cytosine, Uracil and Thymine.

16

Adenine

17

Guanine

18

Cytosine

19

Thymine

20

Uracil

21

One nucleotide strand of a DNA molecule has the base sequence illustrated below.

5'--ATTGCTACGC--3'

Give the base sequence and label the 5' and 3' ends of the complementary DNA nucleotide strand.

5'--ATTGCTACGC--3'

3'--TAACGATGCG--5'

22

If a double-stranded DNA molecule is 15% thymine, what are the percentages of all the other bases?

15% thymine = 15% adenine

35% guanine = 35% cystosine

23

What functions does supercoiling serve for the cell?

Supercoiling compacts the DNA. Negative supercoiling helps to unwind the DNA duplex for replication and transcription.

24

Any group of basic proteins found in chromatin

histones

25

A structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones

nucleosome

26

the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.

chromatin

27

An enzyme that cleaves the chains of nucleotides in nucleic acids into smaller units

nuclease

28

The nucleosome core particle contains two molecules each of histones. These histones are ___, ____, ____, and ____.

H2A

H2B

H3

H4

29

The nucleosome core particle contains two molecules each of histones, which form a protein core with ___ - ____ bp of DNA wound around the core.

145-147

30

For each nucleosome, one molecule of a fifth histone, ___, binds to ___ entering and exiting the nucleosome core to clamp the DNA around the nucleosome.

H1; DNA

31

each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.

chromatid

32

Describe in steps how the double helix of DNA, which is 2nm in width, gives rise to a chromosome that is 700 nm in width.

DNA is first packaged into nucleosomes; the nucleosomes are packed to form a 30-nm fiber. The 30 nm fiber forms a series of loops that pack to form a 250-nm fiber, which in turn coils to form a 700-nm chromatid.

33

Describe the function of the centromere. How are centromeres different from other regions of the chromosome?

Centromeres are the points at which spindle fibers attach to the chromosome. They are necessary for proper segregation of the chromosomes in mitosis and miosis.

34

Nucleosomes at centromeres often possess the variant histone ____.

CenH3

35

The variant histone CenH3 promotes the formation of the _________ to which spindle fibers attach.

kinetochore

36

________ are the ends of the linear chromosome in eukaryotes.

Telomeres

37

Why do telomeres cap and stabilize the ends of the chromosomes?

To prevent degradation by exonucleases or joining of the ends.

38

Telomeres also enable ______ of the ends of the chromosomes by an enzyme called _____.

replication; telomerase

39

The telomeric DNA sequence consists of repeats of a simple sequence, usually in the form of ______.

5'C_n(A/T)_m

40

performed the first chemical analysis of DNA; Isolated “nuclein” from white blood cells (1880’s)

Johann Friedrich Miescher

41

Who found that DNA was essentially a long-chain molecule, made up of four different nucleotides, a ribose sugar, and phosphate?

Phoebus Levene

42

Proteins are composed of up to ___ amino acids

20

43

DNA is composed of __ nucleotides

4

44

Draw the three parts of an RNA nucleotide.

45

The theory that suggested that equal amounts of the four nucleotides were present in all cells

Tetranucleotide Theory

46

•Proteins are composed of up to ___ amino acids

20

47

DNA is composed of __ nucleotides

4

48

In transformation, bacterial cell absorbs DNA from its ________.

environment

49

What are the three processes of gene transfer in bacteria?

Conjugation, transformation, and transduction

50

What is the nucleotide structure in A and B.

Ribose; Deoxyribose

51

Both the ribose and deoxyribose have an OH group on the 5-carbon sugar. What position is it in?

3' carbon

52

Both the ribose and deoxyribose have attached a PO4 group on the 5-carbon sugar. What position is it in?

5' carbon

53

What is the charge of DNA?

Negative

54

Why is DNA negatively charged?

The phosphate group is highly negatively charged.

55

The phosphate group consists of what?

Phosphorous and 4 oxygen molecules.

56

Name each phosphate group in A, B, and C.

A: Monophosphate

B: Diphosphate

C: Triphospate

57

In a nucleotide structure, the bases are nitrogen-containing ring compounds that are either ________ or ______.

pyrimidines; purines

58

A cyclic nitrogenous base has which atoms?

Nitrogen, Carbon, Hydrogen, and Oxygen

59

What type of deoxyribonucleotide structure is this?

Deoxythymidine 5'-monophosphate

(dTMP)

60

What type of deoxyribonucleotide structure is this?

Deoxycytidine 5'-monophosphate 

(dCMP)

61

What type of deoxyribonucleotide structure is this?

Deoxythymidine

5'-monophosphate

(dTMP)

 

62

What type of deoxyribonucleotide structure is this?

Deoxycytidine

5'-monophosphate 

(dCMP)

63

What material makes up the chromosomes?

Chromatin

64

What is chromatin?

DNA + Protein.

It is what makes up the chromosomes.

65

What are the criteria for the genetic material?

Coding

Replication

Expression

Mutation

66

Who isolated the "nuclein" from white blood cells in the 1880s?

Johann Friedrich Miescher

67

What does virulent mean?

Causes disease.

68

What does avirulent mean?

It does not cause disease.

69

When Mr. Griffith was conducting transformation experiments by injecting mice with either the live S bacteria or the live R bacteria, what was the conclusion? 

Live S causes disease.

Live R does not cause disease.

70

When Mr. Griffith was conducting transformation experiments by injecting mice with heat-killed S bacteria, what was the conclusion? 

Heating destroys the disease-causing component in S bacteria.

71

When Mr. Griffith was conducting transformation experiments by injecting mice by mixing live type R and heat-killed S bacteria, what was the conclusion? 

Type R bacteria were transformed into disease-causing S bacteria.

72

What is protease?

The enzyme that degrades proteins.

73

The enzyme that degrades DNA is...

deoxyribonuclease

74

Enzyme that degrades RNA

RNase: Ribonuclease

75

Avery, MacLeod, and McCarty's experiment proved that heat alone did not kill the S bacteria. What was the transforming material?

DNA had to be destroyed.

76

What is semi-conservative replication of DNA?

The new DNA is half old, half new.

 

77

What enzyme chains most nucleotides together in bacterial DNA replication?

DNA Polymerase III

78

What enzyme chews up the RNA primer and replaces the nucleotides deoxynucleotides?

DNA Polymerase 1

79

What enzyme creates a bond on the sugar-phosphate backbone so the new strand is fully chained together?

DNA Ligase

80

What enzyme sits right in the replication fork while breaking hydrogen bonds between base pairs?

DNA Helicase

81

Which gene transfer deals with bacterial cells absorbing DNA from its environment?

transformation

82

What form of DNA is the most common form found in cells?

B cells

83

Who made the first X-Ray Crystallography images of DNA?

Franklin

 

84

Who Analyzed purine and pyrimidine content of DNA from several species?

Chargaff

85

Who did experiments to determine if protein or DNA caused virus infection of bacteria?

Hershey & Chase

 

86

Who did the first experiments on pneumonia infection of mice with rough or smooth bacteria that were live or heat-killed?

Griffith

 

87

Which of these statements about nucleosomes is FALSE?

A) Approximately 145 nucleotide pairs of DNA are wrapped around a nucleosome with another 50 nucleotide pairs linking it to the next nucleosome

B) A nucleosome core is an octomer of 2 molecules each of Histones H2A, H2B, H3 and H4

C) Histone H1 is on the outside of the nucleosome core

D) Histones self-assemble into nucleosomes as the DNA wraps around it

E) Nucleosomes are found in cells of bacteria, plants and animals

E