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66 Cards in this Set
- Front
- Back
Genetics |
study of inheritance & inheritable traits |
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genome |
*entire genetic complement of an organism *includes its genes and nucleotide sequence *genome in bacteria is DNA |
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DNA |
*5 prime- 3 prime *complementary *anti parallel *A-T base pair *C-G base pair *ribose sugar 5 carbon *glucose sugar 6 carbon |
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Structure of prokaryotic Genomes |
prokaryotic chromosomes *main portion of dna, along with associated proteins and rna *haploid *circular molecule DNA in nucleoid |
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Plasmids |
*small molecules of DNA that replicate independently *not essential *helps with survival of bacteria |
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Types of Plasmids |
*fertility factors *resistance factors *bacteriocin facors *virulence plasmids |
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Eukaryotic genomes |
Nuclear chromosomes *have more than one chromosome per cell *chromosomes are LINEAR & IN NUCLEUS *DIPLOID(2 chromosomes) |
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Extranuclear DNA of eukaryots |
*DNA molecules in mitochondria & chloroplast *Resemble chromosomes of prokaryots (DNA wraps around protein (yarn ball) packs together tightly in chromosome) |
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Differences of Prokaryotics and Eukaryotics |
chromosomes b. haploid e. diploid plasmids b. present some e. some algae, fungi & protozoa type nucleic acid b. circular or linear dsDNA e. Linear DNA (nucleus) circular in mitochondria and chloroplast plasmids Location b. nucleoid e.nucleus mitochondria, chloroplast Histones present b.no e.yes |
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DNA replication |
*replication is complementary structure of 2 strands *replication is semiconservative New DNA composed of one original and 1 daughter strand *anabolic polymerization process requires monomers & energy triphosphate deoxyribonucleotides |
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Semiconservative Model of DNA Replication |
Original 1St rep 2nd rep DNA original XXXXXX XXXXXXXX XXXXXX daughter XXXXXX XXXXXXX XXXXXX XXXXXX |
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initial procress in bacterial dna replication |
*replication begins at origin *dna polymerase replicates dna 5'-3' *because strands are antiparallel new srtrands are synthesized differently leading strand continuously smooth lagging strand discontinuously short fragment |
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other characteristics of bacterial dna replication |
*bidirectional *gyrases & topoisomersaes remove supercoils in dna *dna is METHYLATED contols genetic expression initiation of dna replication protection against viral infection repair of dna |
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differences of dna replication in p &e |
e. uses only 4 dna polymerases thousands of replication origins shorter okazi fragments |
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dna replication requires energy but uses no atp why? |
each nucleotide acts as own energy source |
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relationship between genotype & phenotype |
*genotype set of genes in genome *phenotype physical features & functional traits of organisim *genotype determines phenotype |
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transcription |
*info in dna is copied to rna A pairs w/ U C pairs w/ G DNA is boss!!! it gives message to rna and rna takes out of nucleus to orangelles |
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events in transcription |
5 types rna transcribed from dna *rna primers *mRNA *rRNA *tRNA *regulatory RNA occur in nucleoid of prokaryots 3 Steps *initiation *elongation *termination |
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translation |
*polypeptides are synthesized from rna 3 nucleic acid = 1 amino acid messanger RNA transfer RNA ribosomes & ribosomal RNA |
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termination |
*release factors recognize stop codons *modify ribosome to active ribosomers *ribosome dissociates into sub unit-polypeptide released |
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central dogma of genetics |
DNA to mRNA to Protein |
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genetic code extra info |
21 amino acids millions of proteins only 4 nucleic acids capable of 64 arrangements 3 nucleic acids per 1 amino acid |
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Regulation of genetic expression |
*most genes expressed at all times *other genes translated and transcribed when needed conserves energy *Quorum sensing regulates production of some protein detection of secreted quorum sensing molecules can signal bacteria to synthesize a certain protein *Regulation of polypeptide synthesis can: halt transcription stop translation directly |
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Prokaryotic Operons |
*operon consist of a PROMOTER & A SERIES OF GENES * CONTROLLED by a regulatory element OPERATER *typically POLYCISTRONIC (code for sev polyprtides) |
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Nature of prokaryotic operons |
*INDUCIBLE operons activated by INDUCERS LACTOSE operon CATABOLIC *REPRESSIBLE operons transcribed continually until DEACTIVATED by REPRESSORS TRYPTOPHAN operon ANABOLIC |
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mutation |
*change in nucleotide base sequence of a genome *rare event *almost always deletrious *rarely leads to a protein that improves ability of organism to survive |
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types of mutations |
*POINT mutations 1 base pair affected substrations & frameshift mutations *FRAMESHIFT mutations nucleotide triples after the mutation deplaced creates new sequence of codons
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mutagens |
*RADIATION IONIZING NON IONIZING *CHEMICAL (look alike) nucleotide analogs disrupt dna and rna replication *NUCLEOTIDE (Altering chemicals) alter structure of nuceotides result in base line substitutions *FRAMESHIFT result in nonsense mutations |
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frequency of mutations |
*rare events otherwise organisims could not effectively produce *1 out of 10 million contain error *mutagens increase mutation rate 10-100 *many mutations stop transcription or code for nonfunctional proteins |
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which of the following is most likely the number of base pairs in a bacterial chromosome? |
4,000,000 |
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which of the following is a true statement concerning prokaryotic chromosomes? |
they are located in the cytosol |
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a plasmid is |
extrachromosomal DNA |
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which of the following forms ionic bonds with eukaryotic DNA and stabilizes it? |
histone |
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nucleotides used in the replication with DNA |
*carry energy *are found in 4 forms, each with dioxyribose sugar, a phosphate and a base *are present in cells as triphosphate nucleotides d all of the above |
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which of the following moloecules functions as a proof reader for a newly replicated DNA? |
DNA polymerase 3 |
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the addition of -CH3 to a cytosine nucleotide after DNA replication is called______________ |
methylation |
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in translation, the site through which tRNA molecules leave a ribosome is called the ____ |
E site |
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the ames test_______ |
uses autotrophs and liver extract to reveal mutagens |
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which of the following methods of DNA repair involves enzymes that recognize and correct nucleotide errors in unmethylated strands of DNA? |
mismatch repair |
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which of the following is not a mechanism of natural genetic transfer and recombination? |
transcription |
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cells that have the ability to take up DNA from their environment are said to be ____________ |
compotent |
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which of the following statements is true? |
conjunction requires a sex pilus extending from the surface of a cell |
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which of the following are called jumping genes? |
transposons |
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although 2 cells are totally unrelated, 1 cell recieves DNA from the other cell and incorporates this new DNA into its chromosome. this process is___________ |
horizontal gene transfer |
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transcription produces________ |
RNA molecules |
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a nucleotide is composed of_____________ |
a 5 carbon sugar phosphate a nitrogenous base all of the above |
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in DNA, adenine forms_______hydrogen bonds with__________ |
2/thymine |
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a sequence of nucleotides formed during replication of the lagging strand is called______ |
okazaki fragments |
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which of the following is not a part of the operon? |
origin |
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repressible operons are in important in regulating prokaryotic _____________ |
RNA transcription |
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which of the following is part of each molecule of mRNA? |
codon |
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the trp operon is repressible. this means it is usually _________ and is controlled by_________ |
active/repressor |
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the 3 steps RNA transcription are ...... |
initiation, elongation and termination |
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a triplet of mRNA nucleotides that specififies a particular amino acid is called a ______________ |
codon |
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3 effects of point mutations are |
silence, missence, nonsence |
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insertions and deletions and deletions in the genetic code are also called..... |
frameshift mutations |
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an operon consists of ___________, __________ and __________ and is associated with a regulatory gene. |
promoter,operater, series of genes |
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in general, ______ operons are inactive until the substrate of their genes polypeptidee is present. |
inducible |
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a daughter DNA molecule is compromised of one original strand and one new strand because DNA replication is ________________ |
semiconservative |
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a gene for antibiotic resistance can move horizontally among bacterial cells by ________, ____________, and _____________. |
transformation, transduction and bacterial conjunction |
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___________ are nucleotide sequences containing palindromes and genes for proteins that cut DNA strands. |
transposons |
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_________ ______ is a recombination event that occurs during gamete formation in eukaryotes. |
crossing over |
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_________ RNA carries amino acids. |
transfer |
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_______ RNA and _________ RNA are antisense; that is they are complimentary to another nucleic acid molecule |
small interfering/micro |
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ligase plays a major role in _________ |
lagging strand replication |
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before mutations can affect a population permanently, they must be __________ |
lasting inheritable beneficial all of the above |