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112 Cards in this Set

  • Front
  • Back
What macromolecule is involved in ingeritance?
DNA
What are the 2 stages in gene expression?
Transcription & Translation
How did Beadle and Tatum figure out that they had produced bread mold mutants with their X-ray treatments?
The mutants cound not survive on minimal medium.
What exceptions have been found to Beadle and Tatum's one gene-one enzume theory?
Genes code for RNA molecules that code for proteins.
What is produced during the process of transcription?
mRNA, tRNA, rRNA
What macromolecule is involved in ingeritance?
DNA
What are the 2 stages in gene expression?
Transcription & Translation
How did Beadle and Tatum figure out that they had produced bread mold mutants with their X-ray treatments?
The mutants cound not survive on minimal medium.
What exceptions have been found to Beadle and Tatum's one gene-one enzume theory?
Genes code for RNA molecules that code for proteins.
What is produced during the process of transcription?
mRNA, tRNA, rRNA
What is a difference between transcription and translation in eukaryotes and prokaryotes?
In prokaryotes, transcription and translation occur together they are separate in eukaryotes; in eukaryotes, RNA is modified, becoming true mRNA.
What are codons?
Nucleotide triplets.
What codon codes for Met? What does MET stand for?
1. AUG
2. Methionine
Is the genetic code universal? Why or why not?
It is nearly universal because there are exceptions in some unicellular eukaryotes & prokaryotes where codons specify different amino acids.
What enzyme is used in RNA transcription? What are the 3 main stages in transcription?
1. RNA polymerase
2. Initiation, Elongation, & Termination
What are 2 differences between DNA & RNA?
RNA is a copy of DNA.
1. U in RNA; T in DNA
2. RNA is single-stranded & DNA is double-stranded.
What is a promoter & what sequence does it have in a eukaryotic cell?
1. It signals the initiation of RNA transcription.
2. Its sequence is TATA-box-TATAAAA.
What is the difference in the termination of transcription signal in prokaryotes &= eukaryotes?
Prokaryotes: The termination signal in the DNA stops transcription.
Eukaryotes: Cuts the pre-mRNA loose 10-35 nucleotides downstream from stop signal.
What are 2 ways in which eukaryotes modify their pre-mRNA after transcription?
1. The 5' end receives a modified nucleotide cap.
2. The 3' end gets a poly-A tail.
Where in the cell does RNA splicing occur & what stays in the mRNA, the exons or the introns?
1. Nucleus
2. Exons
What makes up the spliceosome & what happens there?
1. Ribosomes
2. RNA is spliced.
What are snRNPs?
Protein snRNA.
What is a ribozyme?
A catalytic RNA molecule that functions as enzymes & can splice RNA.
What RNA molecules are involved in translation? ON which type of RNA molecule do you find the anticodon?`
1. mRNA, tRNA, rRNA
2. tRNA
What is the function of aminoacyl-tRNA synthetase?
They join amino acids to the correct tRNA.
What are ribosomes made of & what process do they take part in?
1. Proteins
2. rRNA
What are the names and functions of the 3 binding sites on ribosomes?
1. P site (peptidyl)-tRNA binding site
2. A site (aminoacyl)-where protein elongates
3. E site-exit site
What happens at the initiation of translation?
The initiation stage brings together mRNA, tRNA, & the 2 subunits of a ribosome.
What happpens at the elongation & termination of translation.
Elongation: Amino acids are added to preceding amino acids.
Termination: Ribosome reaches a stop codon in the mRNA & the whole thing falls apart.
What is polyribosome?
A number of ribosomes translating a single mRNA simultaneously.
How are proteins changed after translation? Give an example of change.
They undergo modificationss such as adding of carbs, lipids, or phospahates; their 3-D shape is changed.
Ex: insulin
What kind of ribosome starts translation & what does it become later if its protein is destined for export from the cell?
1. Free ribosome
2. ER bound ribosome
What must peptides have to make sure they end up at the ER?
Signal peptidefor binding of signal recognition particals.
What kind of mutation changes one base pair in DNA? Can this lead to the production of an abnormal protein?
1. Point mutation
2. Yes.
Is sickle cell anemia a missense or nonsense mutation?
Missense because glutamine codes to valine.
What are frameshift mutations?
The are additions/losses of nucleotide pairs in a gene so the reading frame on mRNA is changed.
What is a mutagen? Give an example of a mutagen.
1. Physical or chemical agents that can cause mutations.
2. Tar from cigarettes.
What is the type of virus that infects bacteria?
Bacteriophages
Who first proved that viruses existed & how did he do it?
Wndell Stanley in 1935. Crystallized infectious particle known as tobacco mosaic virus (TMV)
What are viruses made of?
Nucleic acid enclosed in a protein coat, or sometimes a membraneous envelope.
What can constitute the genome of viruses?
DNA & RNA. Both the DNA & RNA can be single- or double-stranded.
What is a capsid?
Protein that encloses the viral genome.
What sometimes surrounds the capsid & in which viruses is this structure found?
1. Membraneous envelopes
2. Influenza viruses
Describe the structure of bacteriophages.
A capsid that encloses DNA & a protein tailpiece to inject information into a host cell.
Why are viruses called obligate intracellular parasites?
Because they can reproduce only within a host cell.
What are the 2 reproductive cycles in phages & what is different about them?
1. The lytic cycle & lycogenic cycle.
2. The lytic cycle produces new phages & results in the death of the host cell. The lysogenic cycle replicates the phage without destroying the host.
What's the difference between a virulent & a temperate phage?
Virulent uses lytic cycle while temperate uses both lytic & lysogenic cycles.
What are the 2 key variables that are used to classify animal viruses?
1. DNA or RNA
2. Single-stranded or double-stranded.
How do animal viruses bind to their host cells?
Viral glycoproteins on the envelope bind to specific receptor molecules on the surface of the host cell.
How do retroviruses produce their DNA?
They use reverse transcriptase to convert their RNA genome into DNA.
What is a provirus & how is it different from a prophage?
A provirus is the viral DNA that is integrated into the host genome. Unlike a prophage, a provirus remains a permanent resident of the host cell.
What affects do viruses have on infected cells?
They may damage or kill cells by causing the release of hydrolytic enzymes or produce toxins.
What are emerging viruses & give an example?
1. Those that appear suddenly.
2. SARS virus
How do plant viruses spread disease?
Horizontal Transmission & Vertical Transmission
What contributes to genetic diversity in bacteria?
Bacteria forms sex pilus & conjunction to share DNA & mutation.
What does bacterial DNA look like & what are plasmids?
Bacterial DNA is usually a circular DNA molecule with few associated proteins. Plasmids are small circular DNA that can replicate independently of the chromosome.
How do bacteria exchange genetic information?
Transformation, Transduction, Conjunction
What is conjugation between bacteria?
It's the direct transfer of genetic material between bacterial cells that are temporarily joined by by pili.
Do bacteria have male & female? Why or why not?
Yes, males have sex pilus to transfer DNA to the female.
What are R plasmids?
Plasmids that confer resistance to various antibiotics.
What are transposable elements & insertion sequences?
1. "Jumping genes" that contribute to genetic shuffling in bacteria.
2. Simplest transposable elements that exist only in bacteria.
What are 2 ways that bacteria regulate their metabolism?
1. Adjusting activity of metabolic enzymes.
2. Regulating genes that encode metabolic enzymes in operons.
What are operons composed of?
-An operator: "on-off" switch where repressors bind
-A promoter: where RNA polymerase binds
-Genes for metabolic enzymes
What are repressors & corepressors?
1. Switch off proteins
2. Small molecules that work with repressors to switch an operon off
What is a repressible operon & an example?
The trp operon is a repressor operon because it is usually on.
What is an inducible operon & an example?
One that is usually off. Ex. lac operon
What are examples of negative & positive gene expression in bacteria?
1. Repressible operons; enzymes function in anabolic pathways
2. Stimulatory activator; protein such as catabolic activator protein (CAP) in lac protein
What is the source of the DNA pieces & what kind of enzymes are used in gene cloning?
1. The genome & Bacteria placmids.
2. Bacterial reactivation enzyme.
Why would DNA fragments be said to have sticky ends?
Because they are complementary & bind together.
What is the original plasmid called in gen cloning? What is it called after cloning?
1. Cloning vector
2. Recombinant plasmid
What selection criteria do scientists use to figure out which bacteria contains the gene of interest after cloning?
They are identified by the lack of a blue color in bacterial colonis on a medium containing x-galand & picillin.
What is a genomic library?
Collection of recombinant vector clones produced by cloning DNA fragments from an entire genome.
What is a cDNA library?
Complementary DNA of an organisms mRNA inserted in plasmid or phage.
What can a scientist use to avoid gene expression problems that arise from using bacteria & plasmids for gene cloning?
Different expression vectors like YAC.
What is polymerase chain reaction & how does it work?
1. It can produce many copies of a specific target segment of DNA.
2. Uses primers that bracket the desired sequence & DNA polymerase.
How do scientists separate DNA fragments after digestion with restriction enzymes? What is the basis for the separation of the fragments?
1. Gel electrophoresis
2. Negative DNA travels toward positive electrode-small fragments travel faster than large.
What is southern blotting & what is it used for?
1. Specific DNA fragments are identified.
2. Using labeled probes that hybridize to the DNA immobilized on a "blot" of the gel.
What are RFLPs & what can they be used for?
Differences in DNA sequences on homologous chromosomes that result in restriction fragment differences sereve as genetic markers.
What is the human genome project & what are the 2 techniques being used to complete it?
1. Sequencing of the human genome.
2. Genetic (Linkage) Mapping & Physical Mapping
What method is used to sequence short fragments of DNA & how are these sequences put together to figure out the sequence of an entire chromosome?
1. Dideoxy Chain-Termination Method
2. By overlapping/by computer
How do scientists compare patterns of gene expression & function?
Expression: DNA microarray assays
Function: experimental inaction
What kind of useful information can scientists get form comparative studies of genomes from different species?
Help to relate phenotypic similarities with DNA similarities or not.
What are some practical applications of DNA technology?
DNA "fingerprinting" for criminal & paternity testing & gene therapy.
What technique is used to help convict suspects & to establish paternity & what does it involve?
DNA fingerprinting analysis of tissue of body fluids by isolating DNA, digesting & run of gel then identify RFLP markers.
How have bacteria, animals, & plants been genetically engineered to benefit humanity?
Bacteria-Medicine
Animals-More meat
Plants-Healthier Crops
What are some harmful events that may happen because of DNA technology?
The developing of products or procedures that are harmful to humans of the environment.
What are some practical applications of DNA technology?
DNA "fingerprinting" for criminal & paternity testing & gene therapy.
What technique is used to help convict suspects & to establish paternity & what does it involve?
DNA fingerprinting analysis of tissue of body fluids by isolating DNA, digesting & run of gel then identify RFLP markers.
How have bacteria, animals, & plants been genetically engineered to benefit humanity?
Bacteria-Medicine
Animals-More meat
Plants-Healthier Crops
What are some harmful events that may happen because of DNA technology?
The developing of products or procedures that are harmful to humans of the environment.
What are 2 things that researchers hae used to deduce developmental pathways?
Mutations & Molecular genetics
What are 45 model organisms used to study the genetics development?
Fruit Fly, Nematode, Mouse, Zebrafish, & Common Wall Cress
What 3 processes are involved in transforming a zygote into an organism?
Cell division, Cell differation, Morphogenesis
What is the difference between cell differentiation & morphogenesis?
1. Cells become specialized in structure & function.
2. Give shape to the organism & its various parts.
What determines the differences between cells in multicellular organisms? What is genomic equivalence?
1. Gene expression
2. Means you have some genes
What does totipotent mean & what kinds of cells have this characteristic?
1. Capable of generating a complete new organism.
2. Embryonic stem cells
What does pluripotent mean & what kinds of cells have this characteristic?
1. Can only become certain types of cells.
2. Bone marrow cells
How do you clone an entire organism?
Nuclear Transplantation
What was the first mammal to be cloned & when was this accomplished?
Lamb (Dolly) in 1997
What are 3 problems associated with cloning animals?
1. Few embryos survive.
2. Misplacement of DNA methylation may interfere with gene expression.
3. Often get sick at a young age.
What enables differentiated cells to carry out their specific tasks? What are 2 examples of this?
1. Tissue specific proteins from genes.
2. Proteins from myo D in muscle cell & Cytoplasmic determinants in unfertilized egg.
What is induction & its significance in development?
1. Inductions are signals that can cause organ development.
2. Change gene expressions.
What is pattern formation & when does it happen in plants & animals?
1. The development of a spatial organization of tissues & organs.
2. Occurs continually in plants, but is mostly limited to embryos & juveniles in animals.
What is positional information & what does it determine in Drosophila?
1. Molecular cues that detrmine pattern formation or cells location in body. (Segmentation genes, embryonic genes, homeotic genes)
2. Determines the body structure of the organism.
What are 3 types of genes that determine the body axis & segmints in Drosophila?
Sequencial gene expression of maternal effect genes, sementation genes, & homeotic genes.
How early in nematode development are the daughter cells induced to certain pathway? Where do the signals come from?
1. As early as the 4-cell stage.
2. 1 cell in the embryo.
Wht is apoptosis & what are 2 examples of cells in which it happens?
1. Programmed Cell Death
2. White blood cells & C. elegans
Where does embryonic development happen in plants & how does it differ from animal cell development?
1. Inside the seed. Animals are an embryo too.
2. Cell lineage is less important. Homeobox genes don't function the same.
What tissue in plants contains the 3 cell types that are responsible for development?
The floral meristem
What genes in plants are analogous to homeotic genes in animals & what do they control?
1. Organ identity genes
2. Determine the type of structure that will grow from a meristem.
What is the name of the nearly identical nucleotide sequence found in the homeotic genes of vertebrates & invertebrates?
Similar nucleotide sequence has been disolved in the homeotic genes of both vertebrates & invertebrates.
What genes control development in plants & in animals?
Hox gens in animals & mads-box genes in plants.