agricultural genetics chapters 12-17, skip 12.5 and 13.12
Help!
|
|
||||
|---|---|---|---|---|---|
| similarities between bacterial and viral chromosomes | show 🗑
|
||||
| characteristics of viral chromosomes | show 🗑
|
||||
| show | · circular, double stranded, DNA, compacted into nucleoid region
· associated with small proteins: HU and H-NS, other binding proteins made of many (+) charged amino acids
· self-replicated and transcribed readily
🗑
|
||||
| supercoiled DNA | show 🗑
|
||||
| topoisomerases | show 🗑
|
||||
| show | · paired homologs, unusual for eukaryotes
· visualized by light microscopy of nuclei of interphase cells - usually from salivary, rectal, midgut, excretory tissues
· undergo replication with no strand separation or cell division
🗑
|
||||
| puff regions in polytene chromosomes | show 🗑
|
||||
| show | · large with extensive DNA looping, found in vertebrate oocytes and some insect spermatocytes
· isolated from oocytes in diplotene stage of prophase I (meiosis)
· similar to polytene puff regions - high gene activity
🗑
|
||||
| chromatin | show 🗑
|
||||
| histones | show 🗑
|
||||
| nucleosomes | show 🗑
|
||||
| chromatin remodelling | show 🗑
|
||||
| superhelix | show 🗑
|
||||
| chemical modifications | show 🗑
|
||||
| show | · histone acetyltransferase (HAT)
· adds acetyl group to (+) charged amino group on side chain (lysine) -> net charge of protein is now neutral
· increases areas of gene activity
🗑
|
||||
| methylation | show 🗑
|
||||
| show | · kinase
· adds phosphate groups to hydroxyl groups of serine and histidine in histone
🗑
|
||||
| methylation of DNA instead of histone | show 🗑
|
||||
| show | · region of DNA where many cytosine-guanine dinucleotides are present
🗑
|
||||
| show | · uncoiled and active
· appears unstained during interphase
🗑
|
||||
| heterochromatin | show 🗑
|
||||
| show | · repeated many times in eukaryotic chromosomes
· many categories - main ones are highly repetitive or middle repetitive
🗑
|
||||
| show | · highly repetitive
· short repeated sequences that make up a variable portion of total DNA
· found in heterochromic centromeric regions of eukaryotic chromosomes
🗑
|
||||
| centromere | show 🗑
|
||||
| kinetochore proteins | show 🗑
|
||||
| types of moderately repetitive DNA | show 🗑
|
||||
| short interspersed elements (SINES) and long interspersed elements (LINES) | show 🗑
|
||||
| show | · transposable elements generated via RNA intermediate (LINES)
🗑
|
||||
| show | · only 2-10% of eukaryotic genome is protein-encoding genes
· there is a large number of single-copy noncoding pseudogenes: represent evolutionary vestiges, have undergone significant mutation, and are not transcribes
🗑
|
||||
| show | · written in linear form using ribonucleotide bases (RNA)
· codon: every three ribonucleotides
· unambiguous: each codon specifies only one amino acid
· degenerate: 18 of 20 amino acids can be specified by more than one codon
🗑
|
||||
| mRNA | show 🗑
|
||||
| triplet code | show 🗑
|
||||
| reading frame | show 🗑
|
||||
| show | · Nirenberg and Leder developed this to determine some specific codon assignments
· ribosomes bind to single codon of three nucleotides so the complementary amino acid-charged tRNA can bind
🗑
|
||||
| amino acids encoded by only one codon | show 🗑
|
||||
| wobble hypothesis | show 🗑
|
||||
| methionine in bacteria | show 🗑
|
||||
| show | · UAG, UAA, UGA
· do not code for any amino acid, not recognized by tRNA, simply terminates translation
🗑
|
||||
| show | · produce a stop codon early
· translate is terminated and partial polypeptide is produced
🗑
|
||||
| show | · reveals exceptions to the universal genetic code
· UGA codes for tryptophan instead of termination
· AUA codes for methionine instead of isoleucine
🗑
|
||||
| overlapping genes | show 🗑
|
||||
| show | · initiation at different AUG positions out of frame with another lead to distinct polypeptides
🗑
|
||||
| codon vs. anti-codon | show 🗑
|
||||
| RNA polymerase | show 🗑
|
||||
| transcription start site | show 🗑
|
||||
| consensus sequences | show 🗑
|
||||
| transcription termination in bacteria | show 🗑
|
||||
| show | · occurs in nucleus but mRNA leaves nucleus for translation
· chromatin must uncoil (remodeling) to make DNA accessible to RNA polymerases
· RNA pol. rely on transcription factors to scan/bind DNA
· enhancers and silencers regulate transcription
🗑
|
||||
| show | · I -> rRNA
· II -> mRNA, snRNA
· III -> 5SrRNA, tRNA
🗑
|
||||
| show | · transcribes wide range of genes
· activity dependent on cis-acting elements and trans-acting transcription factors
· core promotor determines where it binds to DNA
🗑
|
||||
| TATA box | show 🗑
|
||||
| enhancers and silencers | show 🗑
|
||||
| show | · addition of 5' cap (7-mG cap)
· addition of 3' tail (poly-A tail)
· excision of introns
🗑
|
||||
| show | · regions of initial RNA transcript not expressed in final amino acid sequence
· DNA sequences not represented in final mRNA product
· removed by splicing
· not found in prokaryotes
🗑
|
||||
| self-splicing RNAs | show 🗑
|
||||
| show | · pre-mRNA introns spliced out by spliceosome
· involves formation of lariat structure, splice donor and acceptor sites, branch point sequence
🗑
|
||||
| show | · requires amino acids, mRNA, ribosomes, tRNA
🗑
|
||||
| tRNAS | show 🗑
|
||||
| show | · essential role in expression of genetic information
· consist of large and small subunit
· prokaryotes' are 70s and eukaryotes' are 80s
🗑
|
||||
| rDNA | show 🗑
|
||||
| show | · small and very stable, cloverleaf structure
· 75-90 nucleotides
· transcribed from DNA
· contain post-transcriptionally modified bases
🗑
|
||||
| aminoacylation ("tRNA charging") | show 🗑
|
||||
| initiation of translation | show 🗑
|
||||
| Shine-Dalgarno sequence (bacterial) | show 🗑
|
||||
| show | · mRNAs with several ribosomes translating at once
🗑
|
||||
| show | · ribsosomes larger and longer lived
· transcription in nucleus and translation in cytoplasm - in prokaryotes, both simultaneous in cytoplasm
· needs more factors for initiation, elongation, and termination
· ribsomes not free-floating but bound to ER
🗑
|
||||
| show | · purine (A/G) three bases upstream from AUG start codon, followed by G
· A/GNNAUGG
· thought to increase efficiency of translation by interacting with initiator tRNA
🗑
|
||||
| show | · mRNA cap and tail brought together to form loop
· Poly-A-binding proteins bind to cap-binding protein to form loop
· saves energy by eliminating translation on incomplete mRNA
🗑
|
||||
| show | · dehydration reaction facilitates bond between carboxyl group of one amino acid and amino group of another
· two amino acids linked are dipeptide, three = tripeptide, etc... ten+ = polypeptide
🗑
|
||||
| show | · primary: sequence of amino acids
· secondary: alpha-helix and beta-pleated sheets
· tertiary: three-dimensional conformation
· quaternary: composed of more than one polypeptide chain
🗑
|
||||
| posttranslational modifications | show 🗑
|
||||
| show | · not spontaneous - dependent on chaperones: proteins that mediate folding process
· diseases of protein folding: prion diseases
🗑
|
||||
| show | · point mutation/base subsitution
· missense: different amino acid - gain/loss of function or neutral
· nonsense: early stop codon prematurely terminates translation
· silent mutation: new triplet code but same amino acid (degeneracy)
🗑
|
||||
| show | · transition: pyrimidine replaces pyrimidine (A/G) or puring replaces purine (C/T/U)
· transversion: pyrimidine swapped for purine/vice versa
🗑
|
||||
| show | · result from insertion or deletion of base pair
· frame of reading for triplet code is altered
🗑
|
||||
| Marfan syndrome | show 🗑
|
||||
| show | · loss-of-function: reduces/eliminates function of product
· null: complete loss of function
· dominant: results in mutant phenotype
· gain-of-function: gene has enhanced, negative, or new function
· lethal: death
· conditional: ex. temp-sensitive
🗑
|
||||
| show | · somatic: not heritable, in any cell except germ cells (tumor formation)
· germ-line: heritable, in gametes (trisomy 21)
· autosomal: in autosomes (trisomy 21)
· X- and Y-linked (color blindness, hemophilia)
🗑
|
||||
| induced mutations | show 🗑
|
||||
| show | · loop in template strand during replication -> DNA polymerase misses looped out nucleotides -> insertions and deletions
· more common in repeat sequences (hot spots) - contribute to hereditary diseases (Fragile-X, Huntington)
🗑
|
||||
| show | · alternate chemical forms of purines and pyrimidines - increased chance of mispairing during replication
· tautomeric shifts can change binding structure to allow for noncomplementary base pairing (may be a permanent mutation)
🗑
|
||||
| show | · common causes of spontaneous mutation which can lead to new base pairing
· depurination: loss of purines (A/G) within a site
· deamination: amino group in C/A -> U, A -> hypoxanthine
🗑
|
||||
| oxidative damage to DNA | show 🗑
|
||||
| transposable genetic elements | show 🗑
|
||||
| show | · fungal (aflatoxins)
· cosmic rays
· UV light
· industrial pollutants
· medical x-rays
· chemicals in tobacco smoke or vape products
· micro and nanoplastics
🗑
|
||||
| show | · donate alkyl group (CH3 or CH3CH3) to amino or keto groups in nucleotides
· alter base-pairing affinity and result in transition mutations
· ex. mustard gas (lethal to mammals)
🗑
|
||||
| show | · chemicals that wedge between DNA base pairs -> distortions and unwinding
· ex. ethidium bromide
🗑
|
||||
| show | · covalently binds to DNA, altering conformation and interfering with replication and repair
· ex. acetaldehyde (cigarette smoke) and heterocyclic amines (HCAs, from cooking meats)
🗑
|
||||
| free radicals | show 🗑
|
||||
| beta-Thalassemia | show 🗑
|
||||
| DNA strand discrimination | show 🗑
|
||||
| postreplication repair | show 🗑
|
||||
| photoreactivation repair | show 🗑
|
||||
| xeroderma pigmentosum | show 🗑
|
||||
| diseases caused by defect in NER pathway | show 🗑
|
||||
| show | · DSBs are incredibly dangerous - chromosomal rearrangements, cancer, cell death
· can be repaired by either homologous recombination repair or nonhomologous end joining
🗑
|
||||
| Ames test | show 🗑
|
||||
| transposons | show 🗑
|
||||
| bacterial transposons | show 🗑
|
||||
| transposable elements in the human genome | show 🗑
|
||||
| show | · inducible enzymes: produced only when specific substrates are present to help bacteria adapt to environment
· constitutive enzymes: continuously produced regardless of chemical makeup of environment
🗑
|
||||
| positive vs. negative control | show 🗑
|
||||
| prokaryotic lactose metabolism | show 🗑
|
||||
| show | · three structural genes code for enzyme structure to digest lactose: lac2, lac4, lacA
· upstream regulatory region consisting of operator and promotor
· gene cluster functions to provide rapid response to presence/absence of lactose
🗑
|
||||
| bacterial trp operon | show 🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
junoreg
Popular Agriculture sets