PBIO Final Flashcards
Three Genomes Present in Plants
Mictochondiral, Chloroplast, and Nuclear
Gregor Medel
Worked with pea plants, single gene inheritance and dihybrid crosses
Thomas Hunt Morgan
Used Drosophila to make discoveries in linkage and crossovers. Along with the distance of genes on chromosomes
Barbara McClintock
Used Maize to discover genetic recombination and transposons
Chromatin
Makes up chromosomes, consists of DNA and proteins
Forward Genetics
Genetic mutant’s phenotype is used to help find the mutant’s genotype
Chiasma
Visual manifestaion of a crossover in chromosomes
Recombination
Happens during meiosis in prophase II
Alleles
One of the different forms of a gene that can exist in a single locus
A/a
Indicates heterozygous allales and that they are on separate homologs
AB/ab
Linked in cis
A/a;B/b
Not linked genes
Meselson and Stahl
Used E.Coli to determine that replication was semi-conservative
Sanger
Came up with Sanger/Dideoxy sequencing
Rich Jorgenson
Cosuppression using petunias
Chargaff’s Rule
A=T and G=C
Kary Mullis
Created PCR
Shine-Dalgarno
Sequence in a prokaryotic organism that says the next AUG in the sequence is to be used to initiate translocation
Okazaki Fragmens
Nucelotide fragments that are created while synthesizing the lagging strand
Taq
Enzyme used in PCR because it is extremely heat resistant
Aminoacyl-tRNA synthetase
Joins amino acids to their correspnding tRNA
Ubiquitination
Posttranslational modification that marks a protein for degradtion
Release Factors
Bind to stop codons
Operator
Binds to the bacterial repressor proteins
Three Modifications for mRNA
5’ cap is added, introns are sliced and polyadenylation tail
Intron Splicing
Can lead to multiple proteins from one gene
Dideoxy Sequencing
Sequence is primed and put into a tube with dNTPs, ddATP and DNA polymerase. The dNTPs will pair with the template. If ddATP binds in place of dATP the sequence will stop pairing.
Teleomeres
Are shortened everytime it is synthezied. This can lead to cancer (due to rapid divison) and premature aging.
Genomics
Cloning and molecular characterizatoin of entire genomes
Proteomics
Large scale study of proteins in genomes
Bioinformatics
Group of methods that store, organize, and analyze biological data
Contig Assembly
Cut the genome into random fragments, make library of the fragments, sequence each clone, overlap the sequence reads, and overlap the contigs for a continuous sequence
Ordered-Clone Sequencing
Order large-insert clones by overlaping fingerprints to create a physical map, select clones with minimal overlap, divide into subclones, sequence subclones, assemble the subclones to create the sequence
Microarray
Set of DNAs containing all or more genes in a genome depsited on a small chip
Microarray Process
Exposed to two probes, hybridized, uses laser detection to revel the levels of expression
Yeast Two Hybrid Test
Measures protein-protein interactions
Yeast Two Hybrid Test Process
Binds a bait protein and a target protein to restore the use of the GAL4, one protein is spliced next to the binding domain and another to the activation domain. They are then put into the same yeast cell and observed
IS Elements
Segments of bacterial DNA that can move from one position on a chromosome to a different position on the same or different chromosome, interuppting the expression
Composite Transposons
Variety of gnes that reside between two IS elements that form inverted repeats. Transposase is needed to move the transposon
Simple Transposons
Bacterial genes that are flnaked by inverted repeats, but are too short. They incode their own transposase vs. IS associativity
Replicative Transposition
Copy and paste
Conservative Transposition
Cut and paste
Conintegrate
Replicative transposition happens and there I sone large plasmid that connects the original and new plasmids
Classes of Transposable Elements in Eukaryotes
Retrotransposons and DNA transposons
Retrotransposons
Found by Gerry Fink, employ reverse transcriptase to transpose through an RNA intermediate that produces a double stranded copy
DNA Transposons
Consist of P elements and Ac/Ds elements
P Elements
Resemble simple transposons of bactera because the ends are short Irs and it only encodes a single protein
Ac/Ds Elements
Ac has terminal Irs and transposase. Ds is nonautonomous and cannot encode transposase, so it can’t move on its own
Two Types of Transposons in Humans
LINES and SINES
LINES
Moves like retrotransposons with the help of element-encoded reverse transcirptase
SINES
Short interspersed sequences that are nonautonomous and can’t encode transcriptase
Why Transposons Don’t Jump in Humans
Most are ancient and can no longer moved, plus they are never found in entrons
Synonymous Mutation
aka silent. A codon is altered, but the amino acid remains the same
Conservative Missense
An amino acid is changed, but doesn’t affect the protein function
Nonsense Mutation
Codon is now a stop signal
Indel
Insertions and deletions that can cause frameshifts
Consequences of mutations
Can alter mRNA splicing and can change the protein products
Intercalating Agents
A group of molecuels that mimics the base pairs and are able to slip themselves in between the stacked nitrogen bases at the core of the double helix
Ames Test
Loops to see if a compoud is mutagen by putting the chemical to be metabolized by liver cells and then seeing how it affects his- to his+ conversion
Photo Reactivation
(Direct reversal) The CPD enzyme splits a photdimer to repair the sequence. This requires light
Base Excision
Base is cleaved out out and the DNA is cut, the polymerase synthesizes the new DNA and the ligase seals it
Nucleotide Excision
Uses multiple protein complex to cut and repair, it sometimes need a bypass polymerase. The replication forks and transcription completes
Mismatch
MutS recognizes the mismatch, MutH recognizes the parent and nicks the daughter strand, the new strand is excised and relaced
Translesion
Error prone repair. Bypass polymearse replaced the stalled pol III and continues the synthesis then falls off
Nonhomologus End Joining
Repairs double stranded breaks, but is error prone. It trims the ends of the break and uses ligase to reseal it
SDSA
Reparis double stranded breaks, error free. Ends are trimmed and the broken strand invades its sister chromatin and synthesizes. The DNA unwinds from the template and anneals
Euploid
A cell having any number of complete chromosome sets or an individual organism composed of such cells
Polyploid
A cell with three or more chromosome sets
Autopolyploids
Have multiple chromosome sets originating from one species
Allopolyploids
Have sets from two or more species
Colchicine
Used to induce polyploidy
Aneuploid
Abnormal number of chromosomes
Acentric
A chromosome lacks a centromere
Down Syndrome
Caused by nondisjunction of chromosome 21, resulting in an extra chromosome
Nondisjunction
Chromosomes fail to separate during division
Paracentric Inversion
Inversion happens on the same side of the centromere
Pericentric Inversion
Inversion happens on the other side of the centromere
Reciprocal Translocation
Two chromosomes trade acentric fragments created by two simultanous chromosome breaks
Translocations and Cancer
Alter proto-oncogenes that can result in cancer because a gene is either relocated next to a new regulatory sequence or there is a formation of a hybrid gene
Detect Variation
Through SNPs, microsatillites and haplotypes
Haplotype
Combination of alleles at adjacent locations on a chromosome that are inherited together
HapMap
Genomic wid haplotype map that has been gathered with human population genetics over the last decade
Gene Pool
Sum of total alleles in the breeding members of a population at a given time
Hardy-Weinberg Law
Equation that related the genotype frequencies and allele frequencies to a random mating population P2 + P2Q + P2 = 1
Assumptions
Population is large, mating is random, no immigration/emigration, no natural selection and no mutations
Sources of Variation
Mutations, migration, recombination and genetic drift
Force the Control Variation Fate
Genetic drift and natural selection
Quantitative Genetics
Traits show a continuous range of variation and do not behave in simple Mendelian fashion
QTL
Hereditary continuous variation
Complex Variation
Environmental and genetic
Broad-Sense heritability
Ratio of total genetic variance and total phenotypic variance
Narrow-Sense heritability
Ratio of additive genetic variance and total phenotypic ratio
QTL Mapping
A method for locating QTL in the genome and characterizing the effects of QTL on trait variation
Natural Selection
Darwin theorized that populations change over time as the environment favors features that enhance the ability to survive and reproduce
Neutral Theory of Molecular Evolution
Most mutations in DNA and amino acid replacements between species are fundamentally neutral
Ballard
I learned that there are sesveral different forms of radiation that could cause a population to rapidly diverify into several closely related species