Bacteria Genetics and Lab Techniques

Question 1

If the “sense” strand of a DNA is ATG TAT, what will the mRNA look like?

Answer 1

AUG UAU

Question 2

If the “antisense” strand of a DNA is ATG TAT, what will the mRNA look like?

Answer 2

UAC AUA

Question 3

What are two other names for the “noncoding” strand of DNA?

Answer 3

Antisense or Template strand

Question 4

In an assay for serum antibodies, which sample has more antibodies: the 1:64 titer or the 1:128 titer?

Answer 4

The 1:128 titer (means it is still positive for antibodies at 1:128 dilution)

Question 5

If Trp refers to the amino acid Tryptophan, are bacteria that can grow on Trp-negative medium considered Trp+ or Trp-?

Answer 5

Trp+ (plus means the bacteria can make Trp themselves, don’t need it from the medium)

Question 6

What is another name for the “coding” strand of DNA?

Answer 6

Sense strand

Question 7

What are two other names for the “template” strand of DNA?

Answer 7

Noncoding or Antisense strand

Question 8

DNA homologous recombination requires an overlap of about how many bases at the junction?

Answer 8

~ 20 bases

Question 9

DNA hybridization probes need to be at least how many nucleotides long?

Answer 9

~ 20 nucleotides

Question 10

What kind of blotting detects protein?

Answer 10

Western blots

Question 11

What kind of blotting detects DNA?

Answer 11

Southern blots

Question 12

What kind of blotting detects RNA?

Answer 12

Northern blots

Question 13

What is the only way to detect all DNA mutations with 100% accuracy?

Answer 13

DNA sequencing

Question 14

The human genome has about 25000 genes. How many genes does a typical bacterial genome contain?

Answer 14

~ 4000 genes

Question 15

How many chromosomes does a bacteria have?

Answer 15

1

Question 16

Plasmids are extrachromosomal circles of DNA that contain about how many genes?

Answer 16

1-2

Question 17

Virtually all bacteria have a unique region flanked with universally conserved sequences. What is the name of this region?

Answer 17

16s-RNA (Each 16s-RNA is unique, but it is flanked by conserved sequences that can be used at primer binding sites)

Question 18

What is the name for a set of bacterial genes with related functions that share the same promoter and regulatory elements?

Answer 18

An operon

Question 19

Which of the following are characteristic of bacterial gene expression: RNA splicing, enhancers, operators, repressors, transcription factors, or post-translational protein modification?

Answer 19

Operators and Repressors only

Question 20

Describe a bacterial that is amp- ala- lac-

Answer 20

Is not resistant to ampicillin, cannot make alanine, and cannot digest lactose

Question 21

Describe a bacteria that is pen suc trp

Answer 21

Is resistant to penicillin, can digest sucrose, and can make tryptophan

Question 22

Does a bacterial genome have single-stranded or double-stranded DNA?

Answer 22

double-stranded

Question 23

Is a bacterial genome haploid or diploid?

Answer 23

haploid

Question 24

A chemical that causes a positive Ames test is called what?

Answer 24

A mutagen or carcinogen

Question 25

Bacteria containing what plasmid can transfer genetic material using a sex pilus via conjugation?

Answer 25

the F plasmid

Question 26

What is the name for the process by which DNA in the environment (maybe released from dead bacteria) is taken up non-specifically by live bacteria?

Answer 26

Transformation

Question 27

What is the name for the process by which DNA is transferred between bacteria by a bacteriophage?

Answer 27

Transduction

Question 28

Is generalized transduction carried out by a lytic phage or a lysogenic phage?

Answer 28

Lytic phage (the phage causes bacterium lysis, then picks up DNA released by the dead bacterium)

Question 29

Is specialized transduction carried out by a lytic phage or a lysogenic phage?

Answer 29

Lysogenic phage (the phage inserts itself into the bacterial chromosome, then carries off a piece of adjacent DNA when it leaves)

Question 30

What do R factors carry?

Answer 30

Antibiotic Resistance genes

Question 31

What is the name for a region of bacterial DNA containing several adjacent virulence factors?

Answer 31

a pathogenicity island

Question 32

What is the name for a region of bacterial DNA that can move around the genome, and which often encodes a drug resistance gene?

Answer 32

a transposon

Question 33

Match the following abbreviations (F+ F- Hfr) with the three bacterial descriptions: male with an integrated F plasmid, male without an integrated F factor, and female.

Answer 33

F+ is male, F- is female, Hfr is integrated male