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
