ch. 6 and 7 Genetics
When I is positive (positive interference), it indicates what?
a decrease in the observed number than expected
what are bacteriophages made of?
a protein coat and genetic material
what did the studies of Bateson and Punnett suggest?
a type of coupling in some manner
describe F' factor formation.
a) F factor that contains a part of bacterial chromosome b) It is formed when F factor escapes from bacterial chromosome imprecisely
Genetic recombination by _______________ can produce new combinations of alleles on chromosomes
crossing over
When the known deletion strain has r103 mutated sequence, wild type can be formed from ___________
crossing over
__________: a physical exchange of pieces between homologous chromosomes that most commonly occurs during prophase of meiosis I.
crossing over
Recombinants are from ____________________
crossing over during meiosis
In the experiment by Baetson and Punnett, which of the following observations suggested genetic linkage in the sweet pea? a) A 9:3:3:1 was observed in the F2 offspring b) A 9:3:3:1 was not observed in the F2 offspring c) An unusually high number of F2 offspring had the phenotypes of the P generation. d) both b and c suggested linkage
d
When a crossover occurs, it _____________ the chances of a second crossover.
decreases
_________ is Used on identifying and localizing rII mutations to specific known regions
deletion mapping
A ___________ describes a mating experiment between two organisms that are identically hybrid for two traits.
dihybrid cross
Alfred Sturtevant used the frequency of crossing over in _____________
dihybrid cross
during Nonhomologous /illegitimate recombination, DNA incorporates ________________.
into random sites in the chromosome
____________________ seeks to establish distances between 2 or more mutations within the same gene.
intragenic mapping
____________ is Produced by crossing over between two rII mutants on the same gene but different sites.
intragenic recombination
how are bacterial genes transferred by Hfr strain to F' strain?
laterally
what were the principles of Wollman and Jacob once they completed their experiments? a) Transfer of genes during conjugation was _________ b) Use blender to _____________ between bacterial cells (no harm to the cell) c) The time it took for a gene to enter the recipient cell is directly related to its _______________ (a) The order of genes could be determined by ________________ (b) To determine if genes had been transferred, they used minimal media according to ________________
linear interrupt mating (conjugation) order on the chromosome interrupting mating at different times the gene of interest
Crossing over may alter ________ of genes
linkage
___________: a single chromosome, or all of the genes found on a single chromosome, which are linked together (also called a synteny group)
linkage group
In genetics, a ________ is a specific, fixed position on a chromosome where a particular gene or genetic marker is located.
locus
in the lytic cycle, new phage particles are released through __________________
lyses of bacterial cells
Incorporation of a part of bacterial chromosome may happen during the assembly of new phages during the __________
lytic cycle
_____________: a type of growth cycle for bacteriophage in which the phage directs the synthesis of many copies of genetic material and coat proteins. These components then assemble to make new phages. When synthesis and assembly are completed, the bacterial host cell is lysed, and the newly made phages are released into the environment.
lytic cycle
_____ the relative distance between genes on a single chromosome. In a test cross, it is defined as the number of recombinant genes divided by the total number of offspring, multiplied by 100.
map distance
__________: a unit of map distance obtained from genetic crosses. One of these is equivalent to 1% of recombinant offspring in a testcross.
map unit (mu)
__________: a type of growth medium for microorganisms that contains a mixture of nutrients that are required for growth; nothing additional has been added.
minimal medium
__________ is a unit of measure used in bacterial conjugation experiments ; refers to the relative time it takes for genes to first enter a recipient strain during conjugation.
minutes
________: crossing over that occurs during mitosis and produces a pair of recombinant chromosomes.
mitotic recombination
_____________: a natural process of transformation that occurs in a certain species of bacteria.
natural transformation
in the lytic cycle, inserted phage DNA makes what?
new phage particles
___________: the exchange of DNA between nonhomologous segments of chromosomes or plasmids.
nonhomologous recombination
New allelic combinations produce _______________ cells
nonparental (recombinant)
______: an ascus that contains four spores that all have nonparental combination of alleles.
nonparental ditype
which asci type contains four spores with nonparental combinations?
nonparental ditype
More _____________________ present, the genes are further apart
nonparental offspring
___________: refers to a cell or offspring that carries the same combinations of alleles found in the chromosomes of their parents or in the chromosomes of the parental generation in linkage experiments.
nonrecombinant offspring
a ___________ is a complex of DNA (or RNA) and a protein.
nucleoprotein
___________: a hypothesis that assumes that there is no real difference between the observed and expected values.
null hypothesis
___________: An ascus containing eight ascospores, produced in species in which the tetrad normally undergoes a postmeiotic mitotic division.
octad
____________: the location of an F factor or within the chromosome of an Hfr strain that is the initiation site for transfer of DNA from one bacterium to another during conjugation.
origin of transfer
Cells with original combination of alleles are called ______________________
parental (nonrecombinant) offspring
____________: an ascus that contains four spores with the parental combinations of alleles
parental ditype
which asci type contains four spores with the parental combinations of the alleles only?
parental ditype
what are the different types of asci?
parental ditype (PD) tetratype (T) nonparental ditype (NPD)
____________are viruses that infect bacteria
phages
Donor cell (F+ strain) extends a ________
pilus
Exporter sends nucleoprotein to the recipient cell through _______
pilus
A viral _________ is a visible structure formed after introducing a viral sample to a cell culture grown on some nutrient medium. The virus will replicate and spread, generating regions of cell destruction known as __________.
plaque plaques
Rapid lysis mutant forms large and clearly defined ____________compared to wild-type
plaques
__________ is a general term for a DNA molecule (most often circular) that exists independently of the chromosomal DNA. Some are used as vectors in cloning experiments.
plasmid
Double-crossover rarely occurs due to ______________.
positive interference
___________: a phenomenon in which a crossover that occurs in one region of a chromosome decreases the probability that another crossover will occur nearby.
positive interference
A ______________ is a bacteriophage (often shortened to "phage") genome inserted and integrated into the circular bacterial DNA chromosome or exists as an extrachromosomal plasmid. This is a latent form of a phage, in which the viral genes are present in the bacterium without causing disruption of the bacterial cell.
prophage
what do all types of asci have in common?
they are all tetrads
__________ is a form of genetic transfer between bacterial cells in which a virus (bacteriophage) transfers bacterial DNA from one bacterium to another.
transduction
___________: Transferring bacterial chromosome from one bacterium to another through virus
transduction
__________: when a bacterial cell takes up a plasmid vector segment of chromosomal DNA from the environment.
transformation
____________: when a normal cell is converted to a malignant cell.
transformation
___________: It is the cross between the two individuals of a species for studying inheritance of three pairs of factors or alleles belonging to three different genes.
trihybrid cross
__________ are responsible for mitotic recombination.
twin spots
In ______________, the transfer of genetic material is from parents to offspring. It may be through sexual or asexual reproduction. In contrast, the horizontal gene transfer is the movement of genetic material from a donor organism to a recipient organism that is not its offspring.
vertical gene transfer
Homoallelic mutations will never produce __________ recombinants
wild-type
during step 3 of a trihybrid cross, Parental phenotypes should occur __________ within the offspring
with the greatest frequency
If the rII phages have mutations in different genes, then each phage can complement to produce plaques in _______ This is called what?
K12λ Complementation
When rII phages have mutations in the same gene, they will not be able to make plaque in ______ this is called what?
K12λ Noncomplementation
generalized transduction was first described by:
Lederberg and Zinder (1952) by using Salmonella typhimurium
______________- tests for the goodness of fit between the observed and expected data
Chi square
________ is equivalent to 'gene'
Cistron
_________, also called cis-trans test, in genetics, test for determining whether two mutations associated with a specific phenotype represent two different forms of the same gene (alleles) or are variations of two different genes.
Complementation test
____________ test reveals if two different mutations are in the same gene or not
Complementation test
_________________: Direct physical contact between bacteria
Conjugation
___________________ provide the relative order of genes on a bacterial chromosome and __________________ provides map distances between closely linked genes on the bacterial chromosome
Conjugation experiments cotransduction
conjugation was first studied using what organism?
E. coli
Presence of the ________ allows conjugation from the donor cell
F factor
____________: A DNA sequence or plasmid that confers certain bacteria the ability to produce a sex pilus for conjugation with other bacteria.
F factor
how did the F2 generation in Bateson and Punnett's studies differ than that of Mendel's studies?
F2 showed 15.6:1:1.4:4.5 ratio which differs from expected 9:3:3:1 ratio
__________________: a technique of dna mapping which makes use of extremely rare recombination events where the crossing over occurs between two genes or two alleles of a gene that are only a few nucleotides apart.
Fine structure mapping
______________ is the process by which a segment of DNA is transferred between two bacteria
Gene transfer
__________________ occurs when random pieces of bacterial DNA are packaged into a phage. It happens when a phage is in the lytic stage, at the moment that the viral DNA is packaged into phage heads. If the virus replicates using 'headful packaging', it attempts to fill the head with genetic material.
Generalized transduction
_________________ indicates two genes that are located on the same chromosome
Genetic linkage
________________ determines the linear order of genes on a chromosome
Genetic mapping
transformation was first described by __________________.
Griffith (1928)
___________: a bacterial strain in which the F factor has become integrated into the bacterial chromosome. During conjugation, it can transfer segments of the bacterial chromosome.
Hfr strain
_________________ is one of two cycles of viral reproduction (the lytic cycle being the other). It is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circular replicon in the bacterial cytoplasm.
Lysogenic cycle
which type of phage uses the lytic cycle?
Virulent phages
who mapped E.coli chromosome through conjugation experiment?
Wollman and Jacob in 1950s
Alfred Sturtevant's map was constructed of ________________.
X-linked traits
__________________: Transmission of genes from mother to daughter cells
Vertical gene transfer
_______________ is a strain that lacks the genes necessary to synthesize one or more nutritional requirements
Auxotroph
experiments by Creighton and McClintock discovered what?
(a) Translocation between chromosome 8 and 9 (b) Abnormal chromosome 9 has knob on one end and translocation on the other end (c) Chromosome 9 provide two genes Kernel colored (C) or white (c) Kernel starchy texture (Wx) or waxy texture (wx)
One map unit equals a ____ recombination frequency
1%
Benzer coined ____________ - Smallest genetic unit that gives a negative complementation test
'cistron'
homologous recombination forms __________________ and replaces existing genotypes
'heteroduplex'
Areas of the gene that contain high numbers of mutations are called ______________
'hot spot'
In deletion mapping, rII mutant of interest (r103) was coinfected with ___________________
'known deletion strains'
Chromosomes are often called ____________________
'linkage groups'
Physical location of a particular gene on a chromosome is called _____________
'locus'
T DNA-relaxase complex is called _________________.
'nucleoprotein'
which type of phages use the lysogenic cycle?
'temperate phages'
describe the transformation process.
(1) DNA binds to cell surface competence factor (2) DNA is cut into smaller pieces by extracellular endoculease enzyme (3) Double-stranded DNA is denatured and single stranded DNA enter the cell (4) Integration of foreign DNA into bacterial chromosome
Genetic maps can:
(1) explain the complexity and genetic organization of the species (2) illustrate the principles of particular inherited traits of an organism (3) provide information for gene cloning and other applications for molecular technique (4) be used in evolutionary studies by comparing with other organisms (5) provide practical benefits: diagnosis, prevention of genetic diseases, agricultural use
what were the interpretations of Creighton and McClintock's experiments?
(a) Recombinants were produced (b) Crossing over was seen
describe the first division segregation (fds) pattern.
(a) There is no crossing over between the gene of interest and the centromere (b) Order of allele arrangement is 4:4
How long is the E. coli genetic map?
100 minutes
Mapping by cotransduction experiment can be used to map genes that are within _______________ of each other
2 minutes
Humans have ___ autosomal linkage groups, an __ linkage group, and a ___ linkage group
22 X Y
how many steps are in a trihybrid cross?
5
At map distances approaching ___________________, it is less accurate from actual map distance -Influenced by greater chance of ______________ once it passes 50, it _________________________
50.0 (50% recombination) undetected multiple crossover does not actively reflect map distance
The first genetic map was made by whom?
Alfred Sturtevant (1911)
________________ are viruses that infect bacteria and used extensively in the study of bacteria
Bacteriophages
________________ have a limited capacity for moving bacterial DNA -No more than _______% of the bacterial chromosome
Bacteriophages 1-2.5
Who Discovered two traits that did not assort independently from sweet pea?
Bateson and Punnett (1904)
___________ test reveals if two different mutations are in the same gene or not
Benzer's test
_______________ consists of two homologous chromosomes with a pair of sister-chromatids each
Bivalent chromosomes
describe the fourth step of a trihybrid cross.
Calculate the map distance between pairs of genes
_________________-: Process by which two bacterial genes that are close together are moved by a bacteriophage from one cell to another
Cotransduction
_____________ is the simultaneous transformation of two or more genes.
Cotransformation
_________________ is when two genes are moved into the genome together from environment
Cotransformation
______________ loads the nucleoprotein into the exporter, which is in contact with pilus
Coupling factor
who worked with corn and found chromosomal abnormalities?
Creighton and McClintock
________________: exchange of genetic material between homologous chromosmes
Cross over
who discovered mitotic recombination?
Curt Stern
____________: DNA sequences found in certain species of bacteria that are needed for a DNA fragment to be taken up during transformation.
DNA uptake signal sequences
____________ are located side-by-side in the ascus. This allows the mapping of the distance between a ____________.
Daughter cells gene and centromere of the chromosome
_________________ is a process by which a DNA feature (mutation, DNA polymorphism, or MIC-limited DNA segment) can be genetically mapped to a segment of a MIC chromosome, defined by deletion ends, using a panel of deletion homozygotes.
Deletion mapping
________________ between two genes can rarely occur
Double crossovers
Referring to allelic mutant genes that have mutations at the same site
Homoallelic
___________ is the movement of genes between two different organisms.
Horizontal gene transfer
________________ is the process by which two DNA molecules not sharing homology to each other are joined.
Illegitimate recombination (IR)
_________________ may recombine these mutations and result in wild-type genes
Intragenic crossing over
____________ studies showed that mutations can occur at many different sites within a single gene
Intragenic mapping
____________: Amount of time it takes for an entire chromosome to be transferred during Hfr mating
Minute
who discovered X-linked genes?
Morgan (1911)
what was the biggest take away from Bernard Davis's experiments?
Most, but not all, bacteria can transfer genetic material by conjugation
_____________________ occurs when living bacteria take up DNA from environment
Natural transformation
When the known deletion strain does not have r103 mutated sequence, no plaque is formed regardless crossing over -_____________________
Noncomplementation
_______________ occurs when foreign DNA doesn't have compatible segments with recipient cell.
Nonhomologous /illegitimate recombination
_______________ have the same combinations of alleles as one of the parental strains
Nonrecombinant offspring
describe the second division segregation (sds) pattern.
Order of allele arrangement may be 2:2:2:2 or 2:4:2 -Crossing over occurs between the centromere and the gene of interest (SDS-crossover) (a) The percent of asci containing SDS patterns may be used to calculate the map distance (b) In an SDS, only 1/2 of the spores are product of crossover
__________________-: in which the spores are arranged according to the order in meiotic division.
Ordered Tetrad Analysis
________ acts as an attachment site for the two bacteria
Pilus
_____________ is an area where bacterial lawn on an agar plate is lysed and cleared by phage infection
Plaque
during the lysogenic cycle, ___________ enters into the lytic cycle when it is activated.
Prophage
______________ has all the genes necessary to synthesis nutritional requirements
Prototroph
________________- have different combinations of alleles than either of the parental strains
Recombinant offspring
______________ are fewer in number than _______________ offspring
Recombinants nonrecombinant
_________________ correlates to the distance between genes on a chromosome
Recombination rate
describe the first step of a trihybrid cross.
Step 1) Cross two true-breeding strains that differ with regard to three alleles
describe the second step of a trihybrid cross.
Step 2) Perform a testcross by mating F1 female heterozygotes to homozygous male
describe the third step of a trihybrid cross.
Step 3) Collect the F2 data
what did Bateson and Punnett (1904) study?
Study of flower color and pollen length
_____________: Two or more genes that are located on the same chromosome
Synteny
Relaxome cuts one of the DNA strands forming __________. T DNA separated from its __________________.
T DNA complementary strand
__________: Uses virus as a carrier of genetic material between two bacteria
Transduction
______________: Uptake genetic material from the environment
Transformation
________________ may be used to get map distance and order of genes on chromosome
Trihybrid cross
______________: Adjacent areas of the same organism show different phenotypes
Twin spots
what did the experiment of Bernard Davis utilize?
U-shaped tube with a filter and applied suction and pressure - DNA can go through the filter, but bacteria cannot go through
what are the functions of plasmids on bacteria?
a) Fertility factor: Conjugation b) Resistance plasmids (R factors): Antibiotics resistance c) Degradative plasmids: Digestion of macromolecules d) Col-plasmids: Carry genes for colicines, proteins that kill other bacteria e) Virulence plasmids: Carry genes that make bacteria pathogenic
what are the characteristics of plasmids?
a) The circular extrachromosomal DNA in bacteria b) Plasmids that can integrate into a bacterial chromosome are called 'episomes' (ex.: F factor) c) Plasmids have origin of replication and replicate independently d) Often found many (10-100s) copies per bacterium
Morgan suggested what three hypothesis to explain his results?
a. All three genes are located on the same chromosome (the X chromosome) b. Crossing over produces new combinations of alleles c. The likelihood of crossing over depends on the distance between the two genes
_________: the acquisition of antibiotic resistance by a bacterial strain, which may result from genetic alterations in the bacterial genome, but often occurs because the bacterium has taken up a gene or a plasmid from another bacterial strain.
acquired antibiotic resistance
______________ is the transformation of bacteria that occurs via experimental treatments.
artificial transformation
Genes that are close together tend to be transmitted from parent to offspring _______________.
as a group
________: a sac that contains haploid spores of fungi.
ascus
Fungi are haploid organisms that frequently reproduce ____________.
asexually
_________: a strain that cannot synthesize a particular nutrient and needs that nutrient to be added to its growth medium.
auxotroph
the first studies of conjugation used two _____________ strains. What were these strains?
auxotrophic Biotin and methionine auxotroph ; Phenylalanine and threonine auxotroph
________: a structure in which two pairs of homologous sister chromatids have synapsed (i.e. aligned) with each other.
bivalent
what were the three traits Morgan studied in Drosophila?
body color, eye color and wing shape
what is another term for a map unit?
centimorgan
Relaxase helps T DNA to form _______________.
circular DNA
A ________ is an alternative term for "gene".
cistron
K12λ bacteria are ___________ with two strains of rII
coinfected
______________ are proteins that are needed for bacterial cells to become naturally transformed by extracellular DNA.
competence factors
a ____________ is a peptide secreted by a certain species of bacteria that allows them to become competent for transformation.
competence-stimulating peptide (csp)
________________ are cells that can take up DNA from the environment or an extracellular medium.
competent cells
_________________ occurs when two strains of an organism with different homozygous recessive mutations that produce the same mutant phenotype have offspring that express the wild-type phenotype when mated or crossed. It will ordinarily occur if the mutations are in different genes.
complementation
______________ is a form of genetic transfer between bacteria that involves direct physical interaction between two bacterial cells. One bacterium acts as a donor and transfers the genetic material to the recipient.
conjugation
________________ was first described by Lederberg and Tatum (1946).
conjugation
in the general transduction experiment, the strains were combined and genetic transfer occurred, otherwise known as what?
conjugation
Once contact is made, the pili shorten and bring the bacteria close together, creating a ___________.
conjugation bridge
a __________ is a connection bridge between two bacterial cells that provides a passageway for DNA during conjugation.
conjugation bridge
Most genes for conjugation are contained on ____________________.
conjugative F factors
Genes on a chromosome are physically _______________
connected to one another
what is the fifth step in a trihybrid cross?
construct the map
Genes may be mapped by __________________ in the same manner as cotransduction
cotransformation
Nucleoprotein is exported from the donor cell by help from __________________
coupling factor
Further the genes are apart, the more likely _______________ will occur
crossing over
Genes that are far apart on the same chromosome may assort independently due to _____________.
crossing over
fungi Also reproduce sexually by the fusion of two haploid cells, which Forms _____________. The diploid zygote then proceeds through meiosis to produce ___________________. In some species, this is followed immediately by ___________________________. These cells are contained within a sac called _____________________.
diploid zygote four haploid spores (tetrad) a mitotic division, producing octad an ascus (plural: asci)
F factors may be transferred to a conjugation-defective cell, making it a _______________.
donor cell
the lowest phenotype frequency in a trihybrid cross is indicative that a _____________ is present.
double crossover
which phenotypes indicate which of the three genes is in the middle?
double crossover
Single stranded DNA of both donor and recipient cells replicates and form _______________.
double-stranded DNA
mitotic crossing over is rare on which type of cells?
embryonic
___________: the genetic element that can replicate independently of the chromosomal DNA but can also occasionally integrate into the chromosomal DNA.
episome
Donor strains contain a __________________.
fertility factor (F factor) on a plasmid
Lederberg and Zinder proved bacteriophages as the ______________
filterable agents
There has been no crossing over between the gene and the centromere when two alleles segregate in to separate nuclei at the first division. This is called _______________ and produces the 2:2 (or 4:4 in an octad) pattern
first-division segregation
genetic linkage occurs because...
genes that are close together on the same chromosome tend to be transmitted together to offspring
_________: the phenomenon in which genes that are close together on the same chromosome tend to be transmitted as a unit.
genetic linkage
The linear order of genes on the chromosome is called a _____________________.
genetic linkage map
what is another name for a genetic map?
genetic linkage map
__________: a diagram that shows the relative locations of genes or other DNA segments on a chromosome.
genetic map
_________: any method used to determine the linear order and distance of separation among genes that are linked to each other along the same chromosome. This term is also used to describe the use of genetic crosses to determine the linear order of genes.
genetic mapping
_________: the process in which alleles are assorted and then passed on to offspring in combinations that are different from those that are found in the parents.
genetic recombination
_________: the process in which chromosomes are broken and then rejoined to form a novel genetic combination.
genetic recombination
during Lederberg and Zinder experiment, some bacteria were able to grow on minimal media, which is evidence of ___________.
genetic recombination
___________: the transfer of genetic material from one bacterial cell to another.
genetic transfer
a ________________ is a region of double-stranded DNA that contains one or more base mismatches.
heteroduplex
When two mutations are located exactly on the same location in the gene, they are called _____________
homoallelic
_____________ occurs when foreign DNA has compatible segments with recipient cells.
homologous recombination
_____________: the exchange of similar or identical DNA segments between homologous chromosomes.
homologous recombination
Large percentages of bacterial genomes are the result of _______________________
horizontal gene transfer
_______________ is the transfer of genes from one individual to another individual that is not its offspring.
horizontal gene transfer
Acquired antibiotic resistance may be due to the __________________ of genes from resistant species
horizontal movement
an area of DNA that is likely to mutate (change).
hot spot
Each chromosome contains approximately how many genes?
hundreds to thousands
____________: a method used in conjugation experiments in which the length of time that the bacteria spend conjugating is stopped by a blender treatment or a harsh agitation.
interrupted mating
___________: a strain that does not need a particular nutrient in its growth medium.
prototroph
_____ phages will not infect bacterial strain K12λ
rII
_________: describes DNA molecules that are produced by molecular techniques in which segments of DNA are joined to each other in ways that differ from their original arrangement in their native chromosomal sites. The cloning of DNA into vectors is an example.
recombinant
__________: refers to the cell or offspring that carries a new combination of traits or alleles due to crossing over or due to independent assortment of chromosomes.
recombinant
Testcross allows to distinguish between __________ and ___________.
recombinant and nonrecombinant
Map distance is ______________.
recombinant frequency
Crossing over may produce ___________________.
recombinant genotypes
___________: an offspring that has inherited a combination of alleles or a combination of traits that is different from either of their parents. For unlinked genes, recombinant offspring are produced via independent assortment. For linked genes, recombinant offspring are produced by crossing over.
recombinant offspring
during step 3 of a trihybrid cross, Next highest frequency should be the offspring with a _______________ between one of the genes
recombination event
Probability of a double-crossover in a trihybrid cross is equal to the product of the ______________.
recombination frequency
Most of relaxome proteins are released but ____________ which remains bound to the T DNA
relaxase
In donor cell, a protein complex called _____________ recognizes the origin of transfer on the F factor
relaxome
____________: a protein complex that recognizes the origin of transfer in F factors and other conjugative plasmids, cuts on DNA strand, and aids in the transfer of T DNA.
relaxosome
__________ have both haploid and diploid life cycles
sac fungi
There has been crossing over between the gene and the centromere when two alleles segregate in to separate nuclei at the second division. This is called ____________ and produces the 2:2:2:2 or 2:4:2 (in an octad) patterns (MII pattern).
second-division segregation
_________________: is a structure on the surface of bacterial cells that acts as an attachment site to promote the binding of bacteria to one another.
sex pilus
The arrangement of the spores within an ascus is __________ specific
species
_________: haploid cells that are produced by certain species, such as fungi.
spores
________: the situation in which two or more genes are located on the same chromosome.
synteny
Use _________ to construct genetic linkage map
testcross
_____________: an experimental cross between a recessive individual and an individual whose genotype the experimenter wishes to determine.
testcross
_____________: an experimental cross used for mapping the distance between genes in which an individual that is heterozygous for two or more genes is crossed with an individual that is heterozygous recessive for those same genes.
testcross
__________: a group of four fungal spores contained within an ascus.
tetrad
__________: the structure formed by the association of four sister chromatids during meiosis.
tetrad
________: an ascus that has two spores with the parental combination of alleles and two spores with nonparental combinations.
tetratype
which asci type contains mix of parental and nonparental genotypes in an ascus?
tetratype
When I is negative, it indicates what?
that a crossover enhances the chances of second crossover
what did Bateson and Punnett discover?
that flower color and pollen length were linked
Likelihood of crossing over depends on what?
the distance between two genes
