Microbial genetics

Question 1

Extra chromosomal unit of heredity. It carries with it code for toxicity and antibiotic resistance. Replicates on its own

Answer 1

Plasmid

Question 2

What are the 3 components of DNA nucleotides

Answer 2

Phosphate group, deoxyribose sugar, adenine-guanine-thymine-cytosine bases

Question 3

Functions as a structural part of nucleic acid

Answer 3

Phosphate

Question 4

Function is to express genetic information

Answer 4

Nitrogen bases

Question 5

This RNA is the site of protein synthesis

Answer 5

rRNA

Question 6

This RNA carries amino acids to the ribosome during protein synthesis

Answer 6

tRNA

Question 7

Template for protein synthesis

Answer 7

mRNA

Question 8

2 parental strands of DNA are copied into 2 daughter strands

Answer 8

DNA replication

Question 9

Each cell receives 1 parental strand and 1 daughter strand

Answer 9

semiconservative replication

Question 10

Enzyme that synthesizes 2 nucleotide strands

Answer 10

DNA polymerase (POL III)

Question 11

Enzyme that removes any mistaken base pairs

Answer 11

DNA exonuclease (POL I)

Question 12

Enzyme that seals gaps and joins the 2 strands together

Answer 12

DNA ligase

Question 13

Group of protein that recognize the origin of replication

Answer 13

DNA A Protein

Question 14

Unwind the double helix ahead of replication fork

Answer 14

helicase

Question 15

Remove supercoils that interfere with the further unwinding of the double helix

Answer 15

DNA topoisomerase

Question 16

Leading strand is synthesized continuously in a _____________ direction by DNA polymerase

Answer 16

5’ to 3 ‘ direction

Question 17

Synthesizes a short RNA primer which is extended by DNA polymerase III

Answer 17

RNA polymerase (primase)

Question 18

Enzyme responsible for making mRNA

Answer 18

RNA polymerase

Question 19

Helps the core enzyme attach more tightly to specific deoxyribonucleotide sequence of promoter region

Answer 19

sigma factor

Question 20

Binding of RNAP holoenzyme to template at promoter site

Answer 20

Template binding

Question 21

First nucleotide (usually a purine) associates with initiation site on B subunit of enzyme

Answer 21

Initiation

Question 22

Successive residues are added to 3’ terminus with sequence dictated by base pairing rules

Answer 22

Elongation

Question 23

This must occur to provide access for appropriate base pairing

Answer 23

DNA unwinding

Question 24

Recognizes the termination signal. An ATP-dependent RNA-DNA helicase

Answer 24

rho factor

Question 25

start codon for bacteria

Answer 25

formyl methionine

Question 26

blocks assembly of the ribosome during initiation

Answer 26

streptomycin

Question 27

blocks peptide bond formation during elongation

Answer 27

Chloramphenicol

Question 28

blocks the second site on the ribosome during elongation

Answer 28

Tetracycline

Question 29

blocks translocase during elongation

Answer 29

Erythromycin

Question 30

What is the source of nutrient of bacteria

Answer 30

Glucose

Question 31

the site on a DNA molecule that carries the code for a certain cell function

Answer 31

Gene

Question 32

Process that occurs when a sufficient number of bacteria are present and producing a specific small molecule, virulence, and other genes are turned on

Answer 32

Quorum sensing

Question 33

This protein prevents gene expression by binding to a specific DNA sequence called the operator, blocking the RNA polymerase from initiating transcription at the promoter sequence

Answer 33

Repressor protein

Question 34

Binds to a specific DNA sequence and assists the RNA polymerase in the initiation steps by an unknown mechanism

Answer 34

Apoinducer

Question 35

Responsible for the degradation of the sugar lactose

Answer 35

lactose (lac) operon

Question 36

Indicate low glucose levels and the need to utilize alternative metabolic pathways

Answer 36

Increased cAMP levels

Question 37

Contains the structural genes necessary for tryptophan biosynthesis and is under dual transcriptional control mechanism

Answer 37

tryptophan operon

Question 38

example of operon that exhibits repression

Answer 38

Tryptophan

Question 39

any change in the base sequence of the DNA

Answer 39

mutation

Question 40

type of mutation that involves the addition or deletion of 1 or more bases

Answer 40

Frame shift mutations

Question 41

type of mutation that involves one base change in DNA

Answer 41

point mutation

Question 42

Single base substitution in the 3rd base nucleotide position of a codon. NO change in amino acid

Answer 42

Silent mutation

Question 43

Single base substitution in 1st or 2nd base nucleotide position of a codon. Results in change in amino acid

Answer 43

Missense mutation

Question 44

single base substitution that yield a stop codon

Answer 44

Nonsense mutation

Question 45

Example of alkylating agents

Answer 45

Formalin, nitrogen, mustard, ethylene oxide

Question 46

chemical mutagen that mimics a nitrogen base

Answer 46

base analogs

Question 47

Example of intercalating agents that inserts into DNA and pushes bases apart. It is a chemical produced by peanut and grain molds

Answer 47

Aflatoxin

Question 48

Physical mutagen that causes the formation of t=t dimers

Answer 48

nonionizing radiation

Question 49

Damages DNA by causing the formation of free radicals leading to mutations.

Answer 49

Ionizing radiation

Question 50

Process by which bacteria take up fragments of naked DNA and incorporate them into their genomes

Answer 50

Transformation

Question 51

A mating process between a donor F+( bacteria with fertility factor= plasmid) and an F -recipient cell

Answer 51

Conjugation

Question 52

Big chunks of DNA that randomly excise and relocate on the chromosome

Answer 52

Transposons (jumping genes)

Question 53

Transposition causes antibiotic resistance in this bacteria

Answer 53

Staph. aureus - methicillin resistant Staphylococcus aureus strain

Question 54

the transfer of genetic material from donor bacteria to recipient bacteria via transducing agent

Answer 54

transduction

Question 55

Type of transduction if the phages in question transfer particular genes ( usually those adjacent to their integration sites in the genome)

Answer 55

specialized transduction

Question 56

Type of transduction if incorporation of DNA sequences is random bacause of accidental packaging of host DNA into the phage capsid

Answer 56

Generalized transduction

Question 57

Incorporation of extra chromosomal DNA into the chromosome

Answer 57

Recombination

Question 58

Recombination that occurs between closely related DNA sequences and generally substitutes one sequence for another

Answer 58

Homologous (legitimate) recombination

Question 59

Recombination that occurs between dissimilar DNA sequences and generally produces insertions or deletions or both

Answer 59

Nonhomologous ( illegitimate) recombination

Question 60

Manipulation of the DNA to change its structure

Answer 60

Genetic engineering or recombinant DNA technology

Question 61

What are basic components of genetic engineering

Answer 61

cloning and expression vectors, DNA sequence, enzymes, DNA ligase

Question 62

Engineered to have a site for insertion of foreign DNA

Answer 62

cloning vectors

Question 63

Used to cleave DNA reproducibly at defined sequences

Answer 63

Restriction enzymes

Question 64

Ligation of the vector with the DNA fragments generates a molecule called __________

Answer 64

recombinant DNA

Question 65

The DNA to be cloned can be obtained by purification of chromosomal DNA from cells, viruses, other plasmids or selective amplification of DNA sequences by a technique known as _______

Answer 65

polymerase chain reaction

Question 66

cuts both strands of the DNA in a gene so that the gene will be disabled

Answer 66

Cas 9 protein

Question 67

Uses a single, all purpose enzyme called cas 9 to do the slicing

Answer 67

CRISPR system

Question 68

+ glucose; - lactose

Answer 68

operon off

Question 69

- glucose; + lactose

Answer 69

operon on