CHAPTER 8 PART 2

Question 1

lac operon

Answer 1

set of genes that are regulated together and involved in lactose metabolism in bacteria

Question 2

lac repressor

Answer 2

protein that binds to the operator region of the lac operon, preventing transcription when lactose is not present

Question 3

lac promoter

Answer 3

a region where RNA polymerase binds to initiate transcription of the lac genes

Question 4

lac operator

Answer 4

segment of DNA where the lac repressor binds, blocking RNA polymerase from transcribing the downstream genes

Question 5

lac proteins

Answer 5

include B-galactosidase, permease and transacetylase

Question 6

B-galactosidase

Answer 6

breaks down lactose
aka lacZ

Question 7

permease

Answer 7

facilitates lactose entry
aka lacY

Question 8

transacetylase

Answer 8

involved in lactose metabolism
aka lacA

Question 9

recombination vs recombinant

Answer 9

recombination- process of genetic material exchance
recombinant- refers to organisms that have new combinations of genes

Question 10

horizontal gene transfer

Answer 10

movement of genetic material between organisms (not from parent to offspring, primarily throught conjugation, transformation, or transduction

Question 11

conjugation

Answer 11

transfer of DNA ia direct contact between bacteria

Question 12

F factor

Answer 12

aka fertility factor; plasmid that allows for the formation of conjugative pilus

Question 13

F transfer

Answer 13

involves the transfer of the F plasmid from F+ to F- cells, establishing a new F+ cell

Question 14

Hfr transfer

Answer 14

involves the integration of the F plasmid into the bacterial chromosome, allowing for the transfer of the chromosomal genes along with the f factor

Question 15

transformation

Answer 15

uptake of naked DNA by competent bacteria; can take up and incorporate this DNA from their environment

Question 16

transfection

Answer 16

a similar process to transformation but occurs in euk. cells

Question 17

transduction

Answer 17

transfer of DNA between bacteria via bacteriophages

Question 18

bacteriophages

Answer 18

viruses that infect bacteria

Question 19

two types of transduction

Answer 19

general- any bacterial DNA can be transferred
specialized- specific bacterial genes are transferred due to the integration of the phage DNA into the bacterial genome

Question 20

transposon

Answer 20

a mobile genetic element that can move within and between genomes

Question 21

mutation

Answer 21

a change in nucleotide sequence of DNA

Question 22

wildtype vs mutant strain

Answer 22

wild type- standard form of a gene, while mutant strains have alterations in their genetic makeup

Question 23

spontaneous mutation

Answer 23

occurs naturally without external influence

Question 24

induced mutation

Answer 24

results from exposure to mutagens (substances that cause mutations)

Question 25

missense mutation

Answer 25

changes a single amino acid in a protein due to nucleotide change

Question 26

nonsense mutation

Answer 26

creates a stop codon, terminating protein synthesis prematurely

Question 27

silent mutation

Answer 27

changes a codon but does not alter the amino acid sequence (no impact on protein function).

Question 28

back-mutation

Answer 28

restores the original sequence

Question 29

frame-shift mutation

Answer 29

insertion or deletion of nucleotides that alters the reading frame of the gene

Question 30

SNP

Answer 30

aka single nucleotide polymorphism
a single base change that can affect traits and diseases in humans

Question 31

pharmacogenomics

Answer 31

study of how genes affect a person’s response to drugs

Question 32

in the absense of lactose

Answer 32

the repressor binds to the operator, blocking transcription

Question 33

in the presence of lactose

Answer 33

lactose binds to the repressor
the repressor can no longer bind to the operator, allowing transcription to occur
RNA polymerase transcribes the lac genes into a single mRNA (polycistronic mRNA)