exam 3

Question 1

function of restriction endonuclease?

Answer 1

protect cell from viral attack

Question 2

phage exclusion

Answer 2

variant of restriction enzyme systems that recognize & modify foreign DNA, preventing replication

Question 3

abortive infection

Answer 3

triggers host suicide, leads to programmed cell death by toxin-antitoxin systems

Question 4

what is the function of abortive infection

Answer 4

prevents more virions from being spread, protects population

Question 5

what is CRISPR

Answer 5

major defense system in bacteria & archae, seeks & destroys foreign nucleic acid

Question 6

function of CRISPR

Answer 6

maintains stability & integrity of genome by destroying DNA from horizontal transfer

Question 7

viroids

Answer 7

infectious RNA molecules that lack protein coat

Question 8

function of virioids

Answer 8

doesn’t decode proteins; dependent on enzymes, causes plant diseases

Question 9

prions

Answer 9

infectious proteins whose extracellular form contains no nucleic acid, cause disease in animals

Question 10

genomics

Answer 10

discipline of sequencing, analyzing, and comparing genomes

Question 11

what does a genome tell us?

Answer 11

-metabolic capabilities of an organism
-molecular adaptations to specific environ. (ex. thriving @ high temps.)
-identify virulence factors

Question 12

what kinds of mechanisms do viruses use to avoid CRISPR

Answer 12

-mutation of PAMregions
-production of cas protein inhibitors

Question 13

types of horizontal gene transfer

Answer 13

transformation, transduction, & conjugation

Question 14

how does transformation occur

Answer 14

donor cell lyses, free DNA is taken up by another

Question 15

how does transduction occur

Answer 15

DNA transfer started by a virus

Question 16

how does conjugation occur

Answer 16

DNA transfer that requires cell to cell contact

Question 17

lysogenic conversion

Answer 17

phage inserts specific characteristics into bacterial genes causing bacteria to have better survival

Question 18

systems biology

Answer 18

1. understand functions of specific organism on all possible molecular levels
2. understand structure & function of microbial populations on all possible molecular levels

Question 19

what is nucleic acid hybridization

Answer 19

base pairing of single strands of DNA or RNA from 2 diff. sources to give a hybrid double helix

Question 20

applications of polymerase chain reaction PCR

Answer 20

-identifying specific bacteria
-looking for specific gene
-amplifying small amounts of DNA

Question 21

molecular cloning

Answer 21

isolation & incorporation of a piece of DNA into a vector so it can be replicated & manipulated

Question 22

steps of gene cloning

Answer 22

1. isolation &fragmentation of source DNA
   2.insertion of DNA fragment into cloning vector
2. introduction of cloned DNA into host organism

Question 23

gene fusion

Answer 23

consists segments from different genes

Question 24

operon fusions

Answer 24

coding sequence w its own transitional start site & signals are fused to transcriptional signals of another gene

Question 25

somatotropin

Answer 25

hormone that stimulates growth

Question 26

recombinant bovine somatotropin

Answer 26

is used to stimulate milk production in cows

Question 27

agrobacterium tumefaciens

Answer 27

contains TI plasmid responsible for virulence, contains genes that mobilize DNA for transfer to plant

Question 28

microbiota

Answer 28

microorganisms present at a defined region of our body

Question 29

function of bacteria micrbiome

Answer 29

help digest food, regulate immune system, & protect against other bacteria

Question 30

how is our microbiome influenced

Answer 30

by diet & physical conditions

Question 31

where did the concept of probiotics come from

Answer 31

Elie Mechinikoff proposed that bacteria in fermented milk may be capable to control bacteria in intestinal tract

Question 32

prebiotics

Answer 32

non digestive food ingredient that beneficially affects host by stimulating growth

Question 33

hygiene hypothesis

Answer 33

excessive hygiene w infants results in poorly trained immune system

Question 34

links bw gut microbiota & clinical disease

Answer 34

-increases risk of heart disease & cancers
-in mice: energetic imbalance of microbial gut flora

Question 35

links bw gut microbiota & obesity

Answer 35

gut microbiota of obese people has higher capacity for receiving energy from food than microbiota of slim people

Question 36

normal flora

Answer 36

good bacteria
influences anatomy, physiology, susceptibility to pathogens

Question 37

opportunistic pathogens

Answer 37

infectious pathogen that is dependent in the body but can cause disease when host’s resistance is altered

Question 38

obligate pathogens

Answer 38

never part of normal flora, causes disease
ex. HIV

Question 39

adhesins

Answer 39

proteins on the surface of living cells that allow bacteria to attach to a surface

Question 40

virulence

Answer 40

ability to cause a disease

Question 41

examples of virulence factors

Answer 41

-flagella
-fimbriae
-capsule
-adhesins

Question 42

cytolytic toxins

Answer 42

work by degrading cytoplasmic membrane, causing cell death

Question 43

hemolysin

Answer 43

toxin that lyses red blood cell

Question 44

leukocidin

Answer 44

toxin that lyses white blood cell

Question 45

ab-toxin

Answer 45

causes thick covering in back of throat

Question 46

superantigens

Answer 46

causes overstimulation of immune system, leads to death