Genetics review Flashcards

Terms Definitions
Aneuploidy
Gametes
Sex cells
Genetics
Science of heredity
Helicase
DnaA, DnaB, DnaC
what crosses over?
non-sister chromatids
monoecious
bearing both reproductive structures
 
"one house"
fitness
measures natural selection
+the relative reproductive ability of a genotype. 
Solenoid
a string of nucleosomes.
Origin of Replication
where replication initiates
synapse
early in meiosis homologous chromosomes form pairs in a process called...
Gregor Mendel
Father of modern genetics
peptide bonds
amino acids joined by..
12:3:1
Dominant Epistasis- mutant masks WT
Enhancer
Sequence that stimulates maximal transcription of distant genes; affects only genes on the same DNA molecule, contains short consensus sequences, is not fixed in relation to the transcription start site, can stimulate almost any promoter in its vicinity, and may be upstream or downstream of the gene. The function of an enhancer is independent of sequence orientation.
allele
a factor for a trait
Benzer
crossed by double infection various rII mutants (large, round on B strain) and measured intragenic recombination frequencies to map mutations WITHIN the gene.  
PCR amplification
polymerase chain reaction. uses PRIMERS to double the DNA each cycle.
Complex Characters
Characters that are influenced strongly both by environment and by genes.
Retrotransposon
A transposon with an RNA intermediate
Considering the structure of double stranded DNA, what kinds of bonds hold one complementary strand to the other?
hydrogen
nondisjunction
chromosomes or chromatids fail to disjoin and move to opposite poles
Oogenesis
meiosis in females, begins with diploid cell (oogonium)
 
where can operons be found?
prokaryote genomes
chimera
genetic variation within an individual organism originate from more than one zygote
cytoplasmic inheritance
Inheritance of characteristics encoded by genes located in the cytoplasm. Because the cytoplasm is usually contributed entirely only by one parent, most cytoplasmically inherited characteristics are inherited from a single parent.
deletion mapping
technique for determining the chromosomal location of a gene by studying the association of its phenotype or product with a particular chromosome deletions.
cystic fibrosis
Pleiotropy (effects different organ systems) also allelic heterogeneity
heterozygous
an organism that contains two different alleles for the same trait; in this case the dominant allele shows
frameshift mutation
a mutation caused by frameshift.
Arthur Kornberg
originally isolated DNA polymerase I and won the Nobel Prize in 1959 for its discovery
Transversions
are mutations that result from a purine changing to pyrimidine.
Indels: are mutations that result in frameshift mutations. (insertion or deletion of a single nucleotide)
Pedigree
A diagram listing the members and ancestral relationships in a family; used in the study of human heredity.
Dominant epistasis
12:3:1 ratio resulting from gene interaction along a single pathway.
pedigrees
show the family history of a particular characteristic
What determines if a plants genotype is a heterozygote or homozygote?
self-pollination
Avery, MacLeod, McCarthy
 
Hershey Chase
DNA is transforming substance
 
DNA, not protein is inherited not protein
 
DNA polymerase I
replaces RNA primers with DNA
Point Mutations
Small changes in the DNA Sequence
Transduction
Transfer of bacterial DNA using a bacteriophage, no cell contact required, not sensitive to DNAse
tetrasomy
2n + two extra of same chromosome
endosymbiont theory?
evidence?
the theory that eukaryotes engulfed bacteria cells and are living symbiotically together today
mt and cpDNA are similar to that of bacteria
inhibitors of bacterial translation have same effect on cp and mtDNA but not nuclear DNA.
alzheimers disease
--Mutations in presenilin1 cause early onset autosomal dominant Alzheimer disease --Presenilin protein is a receptor anchored in the Golgi membrane --Monitors beta amyloid usage--30+ missense mutations in presenilin result in beta amyloid accumulation.
Allosteric effect?
inducer binds to repressor changing the shape of the repressor so it cant bind to DNA
cri-du-chat
5p microdeletion. Babies have a 'cat cry' sound. Microcephaly, hypertelorism, mental retardation
5'-capping, 3'-poly(A) tail addition, splicing
Three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes
HT
Probability that a pair of gametes sampled at random from a total population contains two different alleles at a particular locus.
polygenic traits
traits controlled by 2 or more genes
Homologous chromosome
paired chromosomes with genes fro the same traits arranged in the same order
Define "Metaphase"
chromosome line up at the metaphase plate spindle microtubules attach to the centromeres of choromosomes
an operator gene is:
the site for binding repressor
Sister Chromatids
Two chromatids joined by a common centromere. Each chromatid carries identical genetic information.
Gene imprinting
Shut down regions of chromosomes that can depend on which parent the individual inherited the gene from. The parent producing the chromosome can methylate an area of the chromosome to turn off genes.
inversion
in an inversion a section of a chromosome breaks and rejoins with the same chromosome, but in a reversed order. The proper sequence of genes is often important in the coordination of metabolic pathways. if the inversion affects such a pathway then it can have a serious impact.
Dominant
The trait that expresses itself over a recessive
Mitosis leads to the production of two cells with the same number of chromosomes as the parental cell, whilemeiosis leads to the production of gametes with half the chromosome number as the parental cell. (T/F)
True
mutagen
and agent that increases the rate of mutation
allele
Alternative forms of a gene, like tall and short in Mendel's pea plants
Locus
a fixed position on a chromosome that is occupied by a given gene or one of its allele
what are structural blocks of transcription?
methylation and chromatin
gel electrophoresis
a method of molecular separation in which DNA, RNA, or proteins are separated in a gel matrix according to molecular size, with thew use of an electrical field to draw the molecules through the gel in a predetermined direction
Transformation
Stably integrating a piece of DNA into the genome of an organism
A map unit is equal to __________.
1% recombination
Which enzyme or enzymatic activity is not involved in resolution of the Okazaki fragments in E. coli?
RNA ligase
genotype
the genetic makeup or set of alleles of an organism.
Translocation
- occurs when a broken fragment of a chromosome joins with a nonhomologous chromosome
- Down's syndrome can also be caused by the translocation of a chromosome 21 fragment
stem cells
Cells that give rise to other stem cells that retain the potential to differentiate (specialize) further, as well as to cells that differentiate or give rise to cells that differentiate.
cross fertilization
sperm from the pollen of one flower fertilizes the eggs in the flower of a different plant.
sex-linked
an allele that is found on a sex chromosome (X or Y chromosome)
Barr body
is the inactive X chromosome in a female somatic cell,
Different attachment to centromere
localized: microtubules attach at a single regionhalocentric: centromeres throughout the length of chromosome
nucleotide and base excision repair
two types of excision repair
Ribosome, Telomerase, Spliceosome
Enzymes made up of protein and rna
ara operon +
 
When there is arabinose in the cell, it binds to the AraC protein, forming a complex that binds to the araI site.
In addition, the same cAMP-CAP compex that operates in the lac operon must bind to the araI site.

In this configuration, RNA polymerase is attracted to the operon, and begins transcription
Stains and Dyes
-used to produce patterns of bands specific to each Chromosome
Genetic Code
The set of rules by which the nucleotide sequence in an mRNA is translated into an amino acid sequence in a polypeptide.
inheritance of acquired characteristics
all characteristics that are gained during life are passed on
·         How are generalized and specialized transduction different?
Specialized transduction can only transduce at certain point in the bacterial chromosome, in contrast generalized can occur at any point in the bacterial chromosome.
Chargaff
same amount of A as T, and G as C
3' and 5' Carbon
the 2 carbons used to create phosphodiester linkages between nucleotides
Tandem repetitions
Sequences that are repeated in a row. Eg: ATCGATCGATCGATCG
how does transcription happen?
once all the promoters and everything are in place, the RNA polyermase shoots down the coding region, producing a strand of RNA that is complementary to the template strand, replacing the t's with u's.
Nutritional/ Biochemical Mutation
Can not be observed. Affects an organisms ability to make a particular molecule that is essential for growth
leader sequence
the sequence at the 5’ end of an mRNA that is note translated into protein
structure of yeast centromere?
contain a conserved element on each side of an 88 bp A-T rich region where a single microtubule will attach
What does a shaded circle mean? A shaded square?
Affected Female
Affected Male
to study the inheritance of chromosomes in mitosis or meiosis we do this....
identify genetic variants defective in this inheritance 
Blood types
A, B, AB & O; can include Rh factors of + and -
nucleosome and eukaryotic gene expression
proximity of a gene's promoter to nucleosome histones may affect how readily it is transcribed; may block RNA polymerase attachment to TATA box
How can speciation occur through polyploidy?
-typically arises when 2 diploid species hybridize, producing 2N hybrid offspring that are still fertile and reproduce-numerous in angiospermsEx. European salt grass+American salt grass=S. anglicaEx.
How has Recombinant DNA technology been used in the creation of medicines?
By creating strains of bacteria that synthesize human peptides and proteins ie. insulin.
what does an inducer do
binds to the repressor so that the repressor will not bind (thus transcription)
What is the end result of meiosis?
specialized cells that will eventually develop to form gametes.
What is the formula for gene distance.
# of recombinant phenotypes / total number of progeny adn multiply by 100.
linked if RF is less than .5 (P>R)
linkage in relation to recombinance frequency
Waht were the 3 keys to mendel sucess?
1. he started with genetically uniform varieties (true breeding)2.He was able to exactly control which plants mated with each other.3.He examined many genetic crosses adn obtained statistically valid results.
How can RFLPs be used to study evolutionary genetics?
can be used by comparing restriction sites among different individuals of a species to see the genetic structure of a population & assess the evolutionary relationships among organismsEx. African elephant-showed that elephant populations are genetically differentiated across Africa
what are gene mutation rates based on ?
the larger the gene the more likely a mutation.the more repetitive a sequence the more likely a mutation.
angiosperms
flowering plants
genotype ratio
symbols
bacterial DNA
big replicon
Germ line cells
Sex cells
RNA
probably first life form
Phosphodiester bonds
bonds between nucleotides
Genes
The fundamental units of heredity.
The fundamental Mendelian process which involves the separation of contrasting genetic elements at the same locus would be called
segregation
DNA polymerase III
main synthesis enzyme
nullisomy
2n - pair of chromosomes
t/f: most behaviors are polygenic
true
interphase?
G1, S, and G2 phase
joshua lederberg and norton zinder
discovered transduction
Phenylketonuria
The same genotype producing different phenotypes in different environments.
kinase
a protein that transfers phosphate group to amino acid
Wild-type
Most prevalent genotype in the population.
phenotype
any observable characteristic or trait of an organism
Diploid
Cell has two sets of Chromosomes
hotspot
sequence with high frequency of mutations
Crossing-over
Exchanging of parts of chromatids duringmeiosis
de la Chapelle syndrome (male)
XX abnormal
Anaphase 1
Homologous chromosomes separate and move toward opposite poles
submetacentric
centromere located slightly above the center of the chromosomes
replication
semi-conservative is a term applied to
Gene pool
Population of genecopies collectively shared by individuals of a deme. Pop. of potential gametes.
pleiotropic
Referring to genes or mutations that result in multiple phenotypic effects.
Telomerase:
the enzyme involved in maintaining the length of a chromosome between cell division cycles.
Structural Genes
transcribed into mRNA and translated into proteins
Genic Sex Determination
No Sex Chromosomes
 
Genotypes at one or more loci determine the sex of an individual plant or protozoan.
Incomplete Dominance
When heterozygous individuals show a blended intermediate phenotype.
ex. Rr= pink flowers
Mendel's First Law of Inheritance
Principle of Segregation
Both parents are heterozygous for Tay-Sachs disease which is recessive.  If three children in a row were born with Tay-Sachs disease, what are the chances that the fourth child will have Tay-Sachs disease?
A. 0%
B. 25%
C. 50%
D. 75%
 
 
 
B. 25%
hybrid
The offspring of parents of two different species or of two different varieties of one species; the offspring of two parents that differ in one or more inherited traits; an individual that is heterozygous for one or more pairs of genes.
Gametic Mutations
produces an individual with the mutation in both its somatic and germ line cells
anti-parallel
a major breakthrough by Watson and Crick that led to their final model of DNA was the realization that the complementary strands are what
transgene
a gene that has been modifiedand reintroduced into the genome
Blotting
Allows analysis of a single sequence in a mixture
A polymorphism is a genetic difference that exists in at least _____ % of the population (enter a whole number
1
chromosome
coiled structure of DNA and protein that forms in the cell nucleus during cell division; 23 pairs in humans
Cytogenics
study of genetics at a cellular level
monohybrid
an organism that is heterozygous with respect to a single gene of interest.
How do purines and pyimidines differ?
purines are bigger
trisomy 21
condidtion in which someone has three number 21 chromosomes-results froma an error during either stage of meiosis, most commonly during Meiosis I-coomonly known as Down Syndrome
promoter
a regulatory element found in the 5' region of a gene that acts as a binding site for RNA polymerase and regulates the initiation of transcription
 
(regulates the initiation)
Segregation
The separation of members of a gene pair from each other during gamete formation.
Transposons
Sequences of DNA that can move around to different positions within the genome of the cell. Originally discovered by McClintock.
In a pedigree, how is a homozygous reccessive person denoted?
shaded
Pleiotropy
1 gene determines a number of distinct and seemingly unrelated phenotypes
(certain allele being in charge of the color of the flower and seed)
gene regulatory elements
sequences associated with each gene and are involved in regulating transcription
topoisomerase II
maintains 3D conformation of DNA; DNA winder and unwinder
DNA statistics
base pairs are .34 nanometers apart. 360 degree turn takes 10 base pairs per turn. 1,000s of hydrogen bond make the helix stable. Stores Genetic information.
dosage compensation
females have the potential to produce twice the amount of X product as males but this mechanism prevents this: barr body has many epigenetic marks of heterochromatin; exhibit epigenetic inheritance: A cell's daughter cell will have all the same X chromsomes inactivated, though in any given organim one X or the other is randomly inactivated in any cell line.; results in mosaic expression: active allele in any given cell line will be expressed regardless of dominance/recessiveness
Transcript
the RNA molecule copied from the DNA template strand by RNA polymerase
Which of the following chromosomes is an autosome? (chromosome 21, X chromosome, Y chromosome, the mitochondrial chromosome)
chromosome 21
Quantitative Trait
A characteristic that varies in amount of a measurable feature.
Marshall & Warren
-1982-proposed that peptic ulcers are caused by H. pylori-won Nobel prize in 2005
chromatid
one of 2 identical halves of a replicated chromosome
Dihybrid cross
A mating between parents that are both heterozygous for two traits is called a
polygenic
one of a group of nonallelic genes that together control a quantitative characteristic in an organism.
dominant trait
the trait the is expressed in a heterozygous orgamism
catabolic activator protein (CAP)
binds promoter region to activate transcription of structural genes (positive gene regulation)
chromosome theory of inheritance
inherited traits are controlled by genes residing on chromosomes faithfully transmitted through gametes, maintaining genetic continuity from generation to generation
transposable elements
move around the genome and are not susceptible to mismatch or repair
How is recombinant DNA used?
Recombinant DNA technology joins together DNA from 2 or more sources and makes it possible to change the genetic composition of organisms
genetic engineering
a set of technologies that humans use to alter the genetic instructions of an organism by substituting DNA molecules
Gene Therapy
An attempt to treat and possibly cure diseases with cloned genes. Somatic Cell Therapy and Germ-line Cell therapy. Use retrovirus vectors (MLV)Most promising candidates have a simple defect on a single gene
facts about telomeres
repeated DNA, not sticky, universal in vertabrates, controlls amount of cell division
secondary structure
a spiral or zigzag arrangement of the polypeptide chain
caretaker genes
control mutation rates and may have an overall effect, when mutatnt destabilizing the genome
Cell theory
States that all life is composed of cells, that cells arise only from other cells, and that the cell is the fundamental unit of structure and function in living organisms.
Punnett Square
The grid diagram that shows the gene combinations that might result from a genetic cross.
Recombinant DNA Technology
DNA for making insulin in humns is inserted into bacteriaBig vats of bacteria (E.Coli) produce insulin called "humulin"Can be purchased in drug stores
beneficial mutation
a mutation to a gene that makes the protein more functional than before
High Frequency of Recombination(HFR)
Happens when F plasmid integrates into host cell chromosome through recombinationthere is a matching insertion sequence on the chromosome and plasmid which attacks and is where the gene is inserted
Hydrogen Bonding vs Covalent Bonding
Covalent bonds are stronger than hydrogen bonds and are able to bond to most elements on the periodic table. Hydrogen Bonds are only able to bond to oxygen, nitrogen or fluorine.
two modes of RNA interference?
if miRNA is completely complementary to other RNA than it cleaves the RNA and it is rapidly degraded by RNase
if miRNA is only partially complementary then it stays bound to the RNA and represses its espression
What is Variable Expressivity?
When a phenotype that varies in intensity. Individuals with the same genotype for cystic fibrosis have varying levels of symptoms.
dipload vs haploid
somatic and germ cells have 2 sets of chromosomes - diploidgamates have 1 set - haploid
Requirements for DNA replication are:
a single strand DNA or templateraw materials (dNTPs)DNA-polymerase
false (trisomy instead of monosomy)
in humans, autosomal monosomy is the most common type of chromosome aberration
Constitutive mutant?
a gene with a mutation in one of the regulatory genes so that it is turned on all the time. (Operater muation, Repressor gene mutation)
Explain how rats are used to test chemicals for carcinogenic activity.
Repeated application of the carcinogen.
Allele or Factor or Gene
Code for a protein; occur in pairs from mother and father’s genetics
Linkage is an exception to which of Mendel's basic postulates?
the rule of independent assortment
What 4 ways does RNA differ from DNA?
RNA polymerase, one strand AGUC, transcription
Explain how a cell ensures that replication only occurs once since there are so many different origins of replication in eukaryotes?
-DNA uses a licensing factor, which binds to every origin site and once DNA replication machinery initiate replication at these sites, the licensing factor goes away. Replication machinery can ONLY initiate replication on origins that are licensed, so this ensures that it will only occur once
True or False: A plants with the genotype of Pp is heterozygous recessive
False; A gentotype can never be heterozygous recessive only heterozygous dominant
What does the sperm contribute to the egg when fertilization occurs?
The sperm just contriburtes DNA while the egg does the rest. If the mitochondria from the sperm does happen to get inside the ovum, the ovum destroys it.
What were the 7 traits which mendel studied in pea plants?
1) seed form2) seed color3) pod form4) pod color5) flower position6) seed coat color7) stem length
Genetic material
DNA
enzyme
various proteins originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action
purine
one of several purine derivatives, esp. the bases adenine and guanine, which are fundamental constituents of nucleic acids.
probability
the likelihood that a particular event will occur
codominance
a condition in which neither of two alleles of a gene is dominant or recessive
ligase
any of a class of enzymes that catalyze the joining of two molecules by formation of a covalent bond accompanied by the hydrolysis of ATP.
messenger RNA
RNA that copies the coded messahe from the DNA in the nucleus and carries the message to the ribosome in the cytoplasm
A cross is made in E. coli between an Hfr strain that is leu- his- gly-. Interrupted-mating studies show that his+ enters the recipient last. In an interrupted mating b/w the same two strains, his+ recombinants are selected and tested by replica plating f
-his----10.m.u.---gly--4m.u.---leu-
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