Chap 8- Microbial Genetics

Question 1

Mechanisms of genetic change in bacteria

Answer 1

Mutation & Horizontal Gene Transfer

Question 2

changes in existing nucleotide sequence (that is passed on to offspring) “change in genetic material”

Answer 2

Mutation

Question 3

transfer of DNA from one organism to another (bacteria) WITHOUT reproduction

Answer 3

Horizontal Gene Transfer

Question 4

transfer of DNA from parent to progeny (offsprings)

Answer 4

Vertical Gene Transfer

Question 5

Change in organisms DNA alters _____ , which also alters its _______

Answer 5

genotype; phenotype

Question 6

sequence of nucleotides in organism’s DNA

Answer 6

genotype

Question 7

observed characteristics of a cell

Answer 7

phenotype

Question 8

normal , non mutated nucleotide sequence of a species

Answer 8

wild type

Question 9

microorganism that requires organic growth factor

Answer 9

auxotroph (ex: mutant)

Question 10

microorganism that DOES NOT require organic growth factor

Answer 10

prototroph

Question 11

Types of Mutations

Answer 11

Neutral, Beneficial, Harmful

Question 12

Mutation that Has no effect

Answer 12

Neutral

Question 13

mutation that increases fitness of organism

Answer 13

beneficial

Question 14

mutation that decreases fitness/ fatal to organism

Answer 14

harmful

Question 15

random genetic changes passed from normal cell processes that are passed from parent to offspring

Answer 15

spontaneous mutations

Question 16

mutation in which the wrong nucleotide has been incorporated (happens during DNA synthesis)

Answer 16

base substitution

Question 17

change of ONE base pair (in base substitution)

Answer 17

point mutation

Question 18

3 Possible Base Substitutions Outcomes

Answer 18

Silent, Missense, Nonsense

Question 19

mutation that does not change the amino acid encoded (wild type amino acid)

Answer 19

Synonymous (silent) mutation

Question 20

mutation that changes the amino acid encoded by DNA (results in different A.A)

Answer 20

missense mutation

Question 21

mutation that generates a stop codon, resulting in a shortened protein (encodes STOP codon instead of SENSE codon)

Answer 21

Nonsense Mutation

Question 22

Base substitutions that inactivate a gene

Answer 22

Null/ Knockout Mutations

Question 23

Mutation resulting from the addition or deletion of a number of nucleotides not divisible by 3 (results in stop codons/non functional proteins)

Answer 23

frameshift mutation (REALLY BAD)

Question 24

rate of mutation can be increased by a

Answer 24

mutagen

Question 25

Rate of Spontaneous Mutations

Answer 25

1 nucleotide mutated for every 10^9 nucleotides

Question 26

agent that increases change aka (frequency at which DNA is altered (mutated))

Answer 26

mutagen

Question 27

genetic changes that occur due to influence outside of cell

Answer 27

INDUCED MUTAGENS (types- chemical or radiation)

Question 28

Induced Mutation - Radiation) comes in 2 forms

Answer 28

Ionizing and NON Ionizing Radiation

Question 29

causes molecules in cells to become HIGHLY REACTIVE; which can (forms ions that) break backbone of DNA (bc opposite charges attract)

Answer 29

Ionizing Radiation (XRays and Gamma Rays)

Question 30

causes thymine bases to covalently bond to each other (thymine dimers that change shape of DNA), inhibiting transcription and replication

Answer 30

Non Ionizing Radiation (UV rays)

Question 31

Effects of some CHEMICAL Induced Mutagens

Answer 31

modify nucleotides; change their base pairing properties

Question 32

Chemical induced mutagen that converts cytosine to uracil

Answer 32

Nitrus Acid (HN02)

Question 33

Chemical induced mutagen that adds methyl group to Guanine causing it to pair with Thymine

Answer 33

alkylating agents

Question 34

resembles nucleotide but has different properties, causing them to be mistaken by DNA polymerase and stops replication

Answer 34

nucleotide analogs (some chemical behave as this) (chemical induced mutagen)

Question 35

molecules that insert between adjacent base pairs in DNA strand that push nucleotides apart and create space where nucleotides can be added or deleted in New strand

Answer 35

intercalating agents (some chemicals act as this) (chemically induced mutagen)

Question 36

2 Mechanisms for DNA repair

Answer 36

Proofreading Mismatch repair

Question 37

repair done prior to DNA replication; done by DNA polymerase; checks accuracy; can removed incorrect nucleotides, can insert incorrect nucleotides

Answer 37

Proofreading

Question 38

repair that fixes errors missed by DNA polymerase; an enzyme cuts the DNA near a mismatched nucleobase & removes and replacement of a short stretch of nucleotides.

Answer 38

mismatch repair

Question 39

repair where enzyme uses light energy to break covalent bonds of thymine dimers & ONLY found in bacteria

Answer 39

Photoreactivation

Question 40

thymine dimer repair method where enzymes removes damage and DNA Pol and ligase fills & seals gaps

Answer 40

Excision repair

Question 41

process of transfer btwn bacteria where donor cell gives a portion of its total DNA to a recipient cell making it part of recipients DNA

Answer 41

Horizontal Gene Transfer

Question 42

type of horizontal gene transfer where there is uptake of “naked” DNA from the extracellular environment

Answer 42

Bacterial Transformation

Question 43

Griffith experiment showed? and how?

Answer 43

bacteria are capable of transferring genetic information through (transformation) by using encapsulated and un-encapsulated bacteria separately + heat killed together ... where mice were still dying with both heat fixed and pathogenic bacteria introduced at same time.. as only live pathogenic bacteria was extracted from the mice

Question 44

small circular piece of DNA that replicated independently of the cells chromosomal DNA

Answer 44

plasmid (usually transferred via conjugation)

Question 45

plasmids that encode for antibiotic resistance

Answer 45

resistance factors (R factors)

Question 46

encode for enzymes that can catabolize certain sugars or hydrocarbons

Answer 46

Dissimilation plasmids

Question 47

type of horizontal gene transfer in which the donor cell physically contacts the recipient cell (transfer of plasmids)

Answer 47

conjugation

Question 48

donor cell has plasmid that can become sex pilus known as

Answer 48

F factor (fertility factor) or F plasmid

Question 49

F+ plus cells ______; F - cells _______

Answer 49

have F factor; do not have F factor & act as recipient cell