genetics chapter 7

proteins that support chromosomes, receptor proteins, protein hormones, proteins that provide cell shape, enzymes,

....

inversion

180 degree rotation of a segment of a DNA molecule

each gene produces a single enzyme

Beadle and Tatum hypothesized that ___

has a low rate of error

DNA polymerase

ability to proofread and fix mistakes

DNA polymerase has a low rate of error because it has the _____

3' to 5' exonuclease

DNA polymerases use their _____ activity to remove a mismatched base

C-G to T-A transition

Deamination of C to form U followed by DNA replication may result in

HD gene

Huntington disease gene

covalent bonds to form between thymine bases next to each other on the same DNA strand

UV light damages DNA by causing _____

misense mutation

a base substitution in DNA that ultimately leads to a change in the specified amino acid is a ____

transversion mutation

a base substitution in which a purine and pyrimidine are interchanged

substitution mutation

a change in a single base pair in the genetic material is known as ____

substitution

a change of one base for another, different base

reverse mutation

a mutation that changes a mutant allele back to a wild-type

forward mutation

a mutation that changes a wild-type allele to a mutant allele

wide fluctuations in the number of resistant colonies

a prediction of hypothesis 2 (Luria-Delbruck Fluctuation Test) is that different cultures will have ___

slipped mispairing

a second source of mistakes by DNA polymerase is _______

SOS system

a system in bacteria that uses error-prone DNA polymerases

complementation test

a test that determines whether two mutations occur in a single gene or in two different genes

insertion

addition of a block of one or more nucleotide pairs

adenine bonds with cytosine

after a tautomeric shift in adenine ____

random base opposite the apurinic site

after depurination, DNA polymerase will introduce a ______

ethylmethane sulfonate

alkylating agent

transposable element

all DNA segments that move about in a genome, regardless of mechanism

complement each other

alleles of different genes

do not complement each other

alleles of the same gene

different complementation groups

alleles that complement each other

same complementation group

alleles that do not complement each other

mutant allele

an allele that has a different DNA sequence from the wild-type

fluctuation test

an experiment performed by Luria and Delbruck to determine when resistance mutations occurred

mutagen

any agent that can cause mutations at a frequency higher than the spontaneous rate

5-Bromo-uracil

base analog

prototrophic

capable of growth on minimal medium

cistron

complementation group identified by cis/trans test

parents in a complementation test

consist of one individual who is homozygous for a recessive allele and another individual who is homozygous for a different recessive allele

nitrous acid

deaminating agent

tertiary structure

each type of polypeptide has a unique native configuration; this three-dimensional folded shape is known as the protein's ______

intercalators

flat planar molecules that sandwich between DNA bases

FMR-1 gene

fragile X syndrome gene

the identity and the order of amino acids in a polypeptide chaine

genes specify both ____

auxotrophic

grows on minimal medium only if supplemented

hydroxylamine

hydroxylating agent

in response to exposure to the bacteriophage

hypothesis 1 (Luria-Delbruck Fluctuation Test) stated that bacterial resistance occurs _____

due to random mutations

hypothesis 2 (Luria-Delbruck Fluctuation Test) states that resistance is ____

changed permanently

if DNA damage is not repaired before DNA replication, the information content of DNA is ____

about the same number of resistant colonies

if hypothesis 1 is correct, different cultures of bacteria are expected to produce _____

mutant

if the two parents are homozygous for mutant alleles of the same gene, the offspring will inherit two mutant alleles of the same gene (one from each parent) and will have the _____ phenotype

wild type

if the two parents in a complementation test are homozygous for mutant alleles of different genes, the offspring will inherit one recessive mutant and one dominant wild-type allele of each gene, and will have the ____ phenotype

wild-type genotype

in a natural population, a ____ is the most common one

1 in 10^6 bases

in a test tube, the rate at which DNA polymerase incorporate an incorrect bas into DNA is about _____

1 in 10^9 bases

in cells, the rate of error during replication is ____

the covalent bonds between the thymine dimers are broken

in light repair...

once in 10^9 base pairs

in most organisms, the rate of spontaneous mutations introduced during DNA replication is less than..

quaternary stucture

in multimeric proteins, different polypeptides bind together in specific ways, known as the protein's _____

quaternary structure

in multimeric proteins, different polypeptides bind together in specific ways, known as the protein's ______

rat liver enzymes mimic metabolic processes which may produce a mutagen from a harmless compound

in the Ame's test, why were rat liver enzymes included with the compound being tested?

rat liver extract and salmonella bacteria that cannot synthesize histidine

in the Ames test to mutagenicity, the control sample contains....

proflavin

intercalating agent

deletion

loss of a block of one or more nucleotide pairs

bacterial resistance

luria and delbruck devised an experiment to distinguish between two explanations

intercalating agents

mutagens that generate additions

X-rays

mutagens that generate chromosomal rearrangements

X-rays, intercalating agents

mutagens that generate deletions

base analogs, hydroxylating agents, alkylating agents, deaminating agents,

mutagens that generate substitutions

transition, insertion of 1 base pair, deletion of 5 base pairs

mutations in order from most likely to least likely to undergo reversion

cosmic rays and x rays

naturally occurring radiation

sugar phosphate backbone; deletion of DNA bases

naturally occurring radiation can break the _____ and lead to ______

depurination

occurs when A or G base is hydrolyzed, leaving behind a site with no base

the site of a phage infection event

on an agar plate, a lawn of E. coli is spotted here and there with clear round plaques. what do the plaques represent?

tautomers

one reason DNA polymerase makes mistakes is the existence of base _____, alternate forms of bases that pair differently than the usual forms do

the gene sequence

primary structure of a protein is specified directly by ______

features of T4 phages with rII- mutations

produce larger plaques with sharper edges; infect E. coli B strains, but not E.coli K strains

thymine dimers

produced by ultraviolet light

secondary structure

protein regions with special geometry, such as an alpha helix or beta-pleated sheet, are known as protein's _____

mutation

refers to an inherited change in the sequence of the genetic material

deamination

removal of an amino group

unstable trinucleotide repeats

repeated sequences of three bases than can change in number generation after generation are called

wild type bacteria

researchers observed that when _______ are grown in the presence of bacteriophage, a few bacterial cells are resistant

a few bacterial cells are resistant

researchers observed that when wild type bacteria are grown in the presence of bacteriophage, ______

colonies of bacterial cells

resistant bacterial cells survive and divide by binary fission to produce ______

copying repetitive regions of DNA

slipped mispairing can occur when DNA polymerase is ______

occur at a very low rate

spontaneous mutations

one gene, one enzyme

the hypothesis proposed by Beadle and Tatum

damage DNA

the information stored in DNA can change by natural processes that ___

1000-20000 base pairs

the most typical size range for a gene would be

before exposure to the bacteriophage

the results (Luria-Delbruck Fluctuation Test) suggest that mutations produce resistant cells, and that the cells become resistant _____

interactions between amino acids in a polypeptide

the secondary and tertiary structure of a protein are determined by

20 possible amino acids

the sequence of bases of a gene specify the order of amino acids from among the ___

quickly map point mutations to a region

the utility of the deletion mapping approach, as used by Benzer, is to

bacteriophage T4

the virus used to infect E. coli in Seymour Benzer's experiments on fine structure mapping of the rII gene is known as

A to G

transition mutation base change

A to C; G to C; A to T

transversion mutation base changes

huntington disease and fragile X syndrome

trinucleotide repeat disorders

carbonyl and amino

two kinds of chemical groups that represent the ends of a polypeptide

deletions and insertions

types of mutations change the number of nucleotides in a gene

complementation test

way to determine if two recessive mutations that affect the same trait occur in the same gene or in two different genes

ultraviolet light, oxidation, naturally occurring radiation

what can damage DNA

neither DNA replication nor transcription can occur and the organism will probably die

when DNA is damaged by UV light and is NOT repaired

primary structure

when describing a protein's structure, the linear sequence of amino acids is called the _______

complementation

when two different loss-of-function mutants with similar mutant phenotypes are crossed and their progeny are wild-type