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Flashcards in Chapter 8 Deck (65):
1

Transcription

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'Rewriting'

production of mRNA from a DNA template

2

Translation

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"changing the language'

production of a protein in the ribosome using the information carried by the mRNA

3

Genetic Code

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used to translate the nucleotice sequence of mRNA into an amino acid sequence

4

Mutations

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any change in the base sequence of a DNA molecule

5

How many different codons are there in the genetic code?

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64

6

What are the three different types of codons and how many are there of each?

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1. There are 61 sense codons that  code for an amino acid.

 

2. There are 3 nonsense codons that code for a stop in proteins production.  These codons do not code for an amino acid.

 

3. There is 1 start codon that is the ribosome binding site on the mRNA.  This codon codes for the amino acid methionine.

7

List the three different methods for recombination in bacteria.

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1. Transformation

2. Transduction

3. Conjugation

8

What are the two basic typesof mutations?

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Point or base mutations.

 

Frameshift mutations.

9

List 3 ways a mutation might change a protein.

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1. A missense mutation will result in 1 wrong amino acid in the protein.

2. A nonsense mutation will result in an incomplete protein.

3. A frameshift mutation will result in a whole chain of wrong amino acids.

10

Describe the three possible outcomes of a point mutation.

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1. The same amino acid may be coded for resulting in no change in the protein - silent mutation.

2. A wrong amino acid may be coded for resulting in a change in the protein - missense mutation.

3. A premature stop may be coded for resulting in an incomplete protein - nonsense mutation.

11

Anticodon

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is a sequence (three bases) of the tRNA that is complementary to the matching three bases on the mRNA.  The anticodons allows the tRNAs to attached to the codons for the specific amino acid that they carry.

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Codon

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three bases on an mRNA molecule that code for a specific amino acid

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 Ames Test

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A test that utilizes bacteria to identify mutagenic substances.

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Complementary Base Pairing

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The formation of hydrogen bonds between specific pairs of nitrogenous bases. 

In DNA  C bonds to G and A bonds to T.

In RNA C bonds to G and A bond to U.

 

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Competent

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The recipient cell must be competent to take up foreign DNA.

DNA binds to a competent cell the DNA is taken up by the cell the foreign DNA is integrated into the host chromosome.

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Transformation

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the uptake of "naked" DNA by a bacterial cell

(Free floating)

Homologous Recombination

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Transduction

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The exchange of bacterial DNA via a bacteriophage

(carried by a virus)

Homologous Recombination

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Conjugation

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The tranfer of bacterial DNA via a pilus

(requires cell-to-cell contact of two opposite "mating types" F+ and F-)

Homologous Recombination

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Transposition

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movemnet of genes from one place in the DNA to another

"Jumping Genes"

Could be recombinant but more likely to get a mutation

"Random"

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Transfer RNA

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carries the anticodon that matches with the codon on the Messenger RNA and the amino acid coded for by the codon to the ribosome

(61 transfer RNA's)

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Messenger RNA

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is made from DNA by complementary base pairing and carries codons coding for amino acids

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Start Codon

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The codon on the mRNA that the ribosome attaches to to begin translation, AUG.

23

Stop Codon

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 One of three codons that (also known as nonsense codons) that do not code for an amino acid, but mark the end of the coding sequence on mRNA. 

UAA

UAG

UGA

24

Which type of RNA makes up the ribosome?

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Ribosomal RNA (rRNA)

25

Nonsense Mutation

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The type of mutation which changes a sense codon into a nonsence codon, causing an incomplete protein.

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Silent Mutation

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type of mutation where there is no change, the codon has the same amino acid. (EX: UCU-->UCC, both code for the same amino acid)

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Sense Codon

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A set of three nucleotides in a protein coding sequence that specifies individual amino acids

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Point Mutation

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type of mutation in which only a single base is swtiched for the wrong base

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Conjugation

bacterial sex;" the exchange of genetic material from one bacterial cell (donor) to another (recipient) by the close association of the two cells and the passage of the bacterial chromosome or plasmid through the F pilus
 

31

DNA Polymerase Proofreading

 

Removal of mismatched base pairs during DNA replication by the 3' to 5' exonuclease activity of DNA polymerase, followed by resynthesis

32

F Plasmid

 

a conjugative plasmid found in F+ (male) bacterial cells that leads with high frequency to its transfer, and much less often to transfer of the bacterial chromosome, to an F− (female) cell lacking such a plasmid.
 

33

Frameshift Mutation

 

A mutation in a DNA chain that occurs when the number of nucleotides inserted or deleted is not a multiple of three, so that every codon beyond the point of insertion or deletion is read incorrectly during translation.

34

Genetic Code

 

 The nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells
 

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Homologous Recombination

•The exchange of DNA fragments between two DNA molecules or chromatids of paired chromosomes (during crossing over) at the site of identical nucleotide sequences.
 

36

Messenger RNA

 

 The form of RNA in which genetic information transcribed from DNA as a sequence of bases is transferred to a ribosome.
 

37

Missense Mutation

 

In genetics, a missense mutation (a type of nonsynonymous mutation) is a point mutation in which a single nucleotide is changed

38

Mutagen

 An agent, such as radiation or a chemical substance, that causes genetic mutation.
 

39

Mutation

2.The changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations

40

Which of the following pairs is mismatched?
A) DNA polymerase – makes a molecule of DNA from a DNA template
B) RNA polymerase – makes a molecule of RNA from an RNA template
C) DNA ligase – joins segments of DNA
D) Transposase – insertion of DNA segments into DNA
E) DNA gyrase – coils and twists DNA

B) RNA polymerase – makes a molecule of RNA from an RNA template

41

Which of the following is NOT a product of transcription?
A) A new strand of DNA  
C) rRNA   
E) None of the above
B) tRNA    
D) mRNA


A) A new strand of DNA

42

Transformation is the transfer of DNA from a donor to a recipient cell
A) By a bacteriophage.  
D) As naked DNA in solution.
B) By cell-to-cell contact.  
E) By crossing over.
C) By sexual reproduction.

D) As naked DNA in solution

43

Genetic change in bacteria can be brought about by
A) Mutation.    
C) Conjugation. 
E) All of the above.
B) Transduction.   
D) Transformation.  

E) ALL OF THE ABOVE

44

Conjugation differs from reproduction because conjugation
A) Replicates DNA.    
D) Transfers DNA vertically, to new cells.
B) Transcribes DNA to RNA.   
E) Copies RNA to make DNA.
C) Transfers DNA horizontally, to cells in the same generation.


C) Transfers DNA horizontally, to cells in the same generation.

45

An enzyme that makes covalent bonds between nucleotide sequences in DNA is
A) RNA polymerase.  
C) DNA ligase. 
E) Restriction enzyme.
B) Transposase.  
D) DNA polymerase.

DNA LIGASE 

46

 In transcription,
A) DNA is changed to RNA. 
C) DNA is copied to RNA. 
E) DNA is replicated.
B) RNA is copied to DNA. 
D) Proteins are made.

RNA IS COPIED TO DNA

47

An enzyme that copies DNA to make a molecule of RNA is
A) RNA polymerase.  

C) DNA ligase. 

E) Restriction enzyme.

B) Transposase.  

D) DNA polymerase.

RNA POLYMERASE 

48

AM: Transformation is the transfer of DNA from a donor to a recipient cell
A) By a bacteriophage.   D) As naked DNA in solution.
B) By cell-to-cell contact.   E) By crossing over.
C) By sexual reproduction.

 

 D) Conjugation uses cell-to-cell contact and transduction uses a bacteriophage (virus).  Sexual reproduction and crossing over do not occur in bacteria.

 

49

AM:  An enzyme that cuts double-stranded DNA at specific nucleotide sequences.
A) RNA polymerase   C) DNA ligase    E) Restriction enzyme
B) Transposase   D) DNA polymerase

 

E) The polymerases make nucleic acids and DNA ligase connects pieces of DNA.

 

50

What carries coded information for making spescific protein?

a) tRNA

b) mRNA

c) rRNA

d) none of the above

 

V.L.

B. mRNA

51

How many non-sense condons are there?

a) 61

b) 20

c) 3

d) 64

 

V.L.

C. 3

52

___ requires cell-to-cell contact.

a) conjugation

b) transduction

c) tranformation

d) transposition

 

v.l.

A. conjugation

53

The ___ carries  genes for the synthesis of fertility.

a) vector

b) transposons

c) plasmid

d) operons

 

v.l.

C. plasmid

54

Which mutation will cause the DNA sequence to be completely wrong?

a) point

b) frame-shift

c) missence

d) silent

v.l

B. frame-shift

55

RM

Which chemical is know to be a mutagen?

Nitrous Acid

56

In the operon model, what is between the promoter and the structural genes?

a) restriction enzymes

b) regulator gene

c) siRNA

d) operator

d) operator

57

What is the intermediate between permanent DNA storage (DNA) and the process that uses that information (translation)?

a) tRNA

b) operon

c) ribosome

d) mRNA

d) mRNA

58

Which is an example of a frame-shift mutation?

a) sickle cell anemia

b) diabetes

c) influenza

d) Huntington's disease

d) Huntington's disease

59

Another term for point mutation is

a) missense

b) codon

c) base substitution

d) anticodon

c) base substitution

60

Describe prokaryotic genetic exchange:

a) horizontal gene transfer

b) vertical gene transfer

c) asexual

d) a and c

d) a and c

61

How is transposition different from other methods of genetic transfer?

a) it is homologous recombination

b) it occurs once every second

c) it will likely cause damaging mutations

d) it occurs in prokaryotes

c) transposition will likely cause damaging mutations

62

How many TRNA's are there?                MP

61, same as sense codons        MP

63

What form of binary fission involves Fertility Plasmids?     MP

Conjugation                        MP

64

 

G.L. How many different tRNA are made for each mRNA?

 

a) 64

b) 61

c ) 20

d ) 3

 

 

G.L. b) 61

65

 

G.L. Transduction is the exchange of DNA via..

 

    a) sex pili

   b) naked DNA in the solution

    c) binary fission

    d) bacteriophage

 

 

G.L. d) bacteriophage