EFB-307 Genetics, F2009 Exam 2
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- L8 - GENE & CHROMOSOME MUTATION DISOMIC (haploids)
- DISOMIC (haploids): n+1
- L8 - GENE & CHROMOSOME MUTATION FOUNDER MUTATION
- FOUNDER MUTATION: A mutation carried the ancestral founder of a distinct population.
- L8 - GENE & CHROMOSOME MUTATION What 7 human conditions have roots in founder mutations?
- 1. Iron overload 2. Cystic fibrosis 3. Sickle cell disease 4. Blood clots 5. Alcohol toxicity 6. Lactose tolerants 7. Deafness
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: There are no advantages to being heterozygous for a founder mutation.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION What are the 3 main types of mutations?
- 1. Single-gene mutations 2. Chromosome mutations 3. Genome mutations
- L8 - GENE & CHROMOSOME MUTATION SINGLE-GENE MUTATION
- SINGLE-GENE MUTATION: Relatively small change in DNA structure that occurs within a specific gene.
- L8 - GENE & CHROMOSOME MUTATION What 2 sites in a gene can a SINGLE-GENE MUTATION alter?
- 1. Promoter 2. Transcriptional unit
- L8 - GENE & CHROMOSOME MUTATION CHROMOSOME MUTATION
- CHROMOSOME MUTATION: Change in the chromosome structure.
- L8 - GENE & CHROMOSOME MUTATION GENOME MUTATION
- GENOME MUTATION: Change in the chromosome number.
- L8 - GENE & CHROMOSOME MUTATION ALLELE
- ALLELE: One of the different forms of a gene that exists at a single locus.
- L8 - GENE & CHROMOSOME MUTATION LOCUS
- LOCUS: Location of a gene on the chromosome.
- L8 - GENE & CHROMOSOME MUTATION MUTATE
- MUTATE: To change.
- L8 - GENE & CHROMOSOME MUTATION In what 2 ways are alleles generated?
- 1. Recombination of functional gene domains 2. Gene mutation
- L8 - GENE & CHROMOSOME MUTATION What are the 3 gene-altering effects on base (A,C,G,T) generation?
- 1. Deletions 2. Additions 3. Substitutions
- L8 - GENE & CHROMOSOME MUTATION WILD-TYPE (wt)
- WILD-TYPE (wt): Designated standard allele.
- L8 - GENE & CHROMOSOME MUTATION FORWARD MUTATION
- FORWARD MUTATION: Any change away from the wild-type allele.
- L8 - GENE & CHROMOSOME MUTATION REVERSE MUTATION
- REVERSE MUTATION (REVERSION/BACK MUTATION): Any change back to the the wild-type allele.
- L8 - GENE & CHROMOSOME MUTATION IGF1 allele encodes what?
- IGF1 allele encodes an insulin-like growth factor.
- L8 - GENE & CHROMOSOME MUTATION IGF1 allele affects what?
- IGF1 allele is the major determinate of dog size.
- L8 - GENE & CHROMOSOME MUTATION IGF1 allele is present and absent in what?
- IGF1 allele is present in small dog breeds. IGF1 allele is absent in giant dog breeds.
- L8 - GENE & CHROMOSOME MUTATION HAPLOTYPE
- HAPLOTYPE: A specific combination of alleles/sequence variations that can be inherited together.
- L8 - GENE & CHROMOSOME MUTATION POLYMORPHISM
- POLYMORPHISM: A sequence variation at a given chromosomal location that is common in a population.
- L8 - GENE & CHROMOSOME MUTATION SINGLE NUCLEOTIDE POLYMORPHISM (SNP)
- SINGLE NUCLEOTIDE POLYMORPHISM (SNP): A single-basepair variation in a DNA sequence that is common to a population.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Size is a quantitative trait.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION IGF1 allele consists of what haplotype?
- SNP (single-nucleotide polymorphism).
- L8 - GENE & CHROMOSOME MUTATION What are the 6 agents of gene mutations?
- 1. DNA replication errors 2. Reactive cellular metabolites 3. Chemicals 4. High-energy radiation 5. Mobile genetic elements 6. Viruses
- L8 - GENE & CHROMOSOME MUTATION What are the 3 steps to gene mutation?
- 1. Mutagenic agents/events 2. Premutational gene damage 3. Repair-system activity
- L8 - GENE & CHROMOSOME MUTATION What 3 agents of gene mutation can have no repair-system activity take place?
- 1. DNA replication errors 2. Mobile genetic elements 3. Viruses
- L8 - GENE & CHROMOSOME MUTATION In what 3 ways does the genetic repair-system deal with premutational damage?
- 1. Cuts out damaged DNA segment; replace with DNA generated from template 2. Reverses damage 3. Bypasses lethal replication block by accepting mutated base
- L8 - GENE & CHROMOSOME MUTATION What is the result of no repair-system activity on premutational damage caused by DNA replication errors?
- Expansion of small repeat.
- L8 - GENE & CHROMOSOME MUTATION What is the result of no repair-system activity on premutational damage caused by mobile genetic elements or viruses?
- DNA insertion.
- L8 - GENE & CHROMOSOME MUTATION What is the result of premutation damage being cut out and replaced with template DNA by the repair-system?
- No mutation.
- L8 - GENE & CHROMOSOME MUTATION What is the result of premutational damage reversal by the repair-system?
- No mutation.
- L8 - GENE & CHROMOSOME MUTATION What is the result of the repair-system's attempt to bypass a lethal replication block by accepted a mutated base?
- Base-pair substitution.
- L8 - GENE & CHROMOSOME MUTATION POINT MUTATION
- POINT MUTATION: Change in a single basepair via base substitution. 5'-AACGCTAGATC-3' becomes 5'-AACGCGAGATC-3'
- L8 - GENE & CHROMOSOME MUTATION TRANSITION
- TRANSITION: Change of a pyrimidine (C,T) into another pyrimidine (C,T) -or- Change of a purine (A,G) into another purine (A,G).
- L8 - GENE & CHROMOSOME MUTATION TRANSVERSION
- Change of a pyrimidine (C,T) to a purine (A,G) or vice versa.
- L8 - GENE & CHROMOSOME MUTATION PYRIMIDINE BASES
- PYRIMIDINE BASES: C, T
- L8 - GENE & CHROMOSOME MUTATION PURINE BASES
- PURINE BASES: A, G
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Transitions are more common than transversions.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION What is the consequence of addition/deletion mutations?
- Frameshift
- L8 - GENE & CHROMOSOME MUTATION What are the 3 consequences of base substitution mutations?
- 1. Silent 2. Missense 3. Nonsense
- L8 - GENE & CHROMOSOME MUTATION NONSENSE MUTATION
- NONSENSE MUTATION: Produces a premature stop codon.
- L8 - GENE & CHROMOSOME MUTATION SUPPRESSOR MUTATION
- SUPPRESSOR MUTATION: Produces a mutant tRNA anticodon that suppresses codon mutations.
- L8 - GENE & CHROMOSOME MUTATION Thymine residues along a DNA backbone, irradiated with UV light, form what?
- Thymine photodimer.
- L8 - GENE & CHROMOSOME MUTATION SLIPPAGE MUTATION
- SLIPPAGE MUTATION: When DNA replication slips at repeated bases and either adds extra nucleotides or misses adding needed nucleotides.
- L8 - GENE & CHROMOSOME MUTATION What are 2 diseases caused by trinucleotide repeats?
- 1. Huntington disease (HD) 2. Fragile X syndrome (FRAXA)
- L8 - GENE & CHROMOSOME MUTATION TRINUCLEOTIDE REPEAT (TNRE)
- TRINUCLEOTIDE REPEAT (TNRE): Phenomenon where a sequence of 3 nucleotides increases from one generation to the next.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: In individuals without TNRE mutations, there are still regions of the chromosome with trinucleotide repeats.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION What 2 conditions occur in persons with TNRE disorders?
- 1. Trinucleotide repeats increase above a certain critical size. 2. Trinucleotide repeats become prone to frequent expansion.
- L8 - GENE & CHROMOSOME MUTATION What protein base is most susceptible to expansion by TNRE disorders?
- CAG (glutamine).
- L8 - GENE & CHROMOSOME MUTATION What is the effect of glutamine expansion in individuals with TNRE disorders?
- Proteins include long chains of glutamine that cause them to aggregate together.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Protein aggregation in individuals with TNRE disorders is not correlated to the progression of their disease.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION What are the 2 features of TNRE disorder inheritance?
- 1. Disorder severity worsens in future generations (ANTICIPATION) 2. Disorder severity is dependent on whether it is inherited from the father or the mother.
- L8 - GENE & CHROMOSOME MUTATION ANTICIPATION
- ANTICIPATION: When genetic disorder severity worsens in future generations.
- L8 - GENE & CHROMOSOME MUTATION In HD, the TNRE worsens if inherited from which parent?
- Father
- L8 - GENE & CHROMOSOME MUTATION In myotonic muscular dystrophy, the TNRE worsens if inherited from which parent?
- Mother
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: The genetic origins of TNRE are well-understood.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION What is the most common cause of gene mutation?
- DNA replication errors
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: DNA replication is inherently inaccurate.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Cancers develop faster in cells that divide quickly.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION The inherent inaccuracy of DNA replication is advantageous to what?
- Viruses
- L8 - GENE & CHROMOSOME MUTATION MUTATION RATE
- MUTATION RATE: Likelihood that a gene will be altered by a new mutation. Expressed as (# of new mutations in a given gene) per generation.
- L8 - GENE & CHROMOSOME MUTATION What is the range of mutation rates per generation?
- 10-5 to 10-9 per generation.
- L8 - GENE & CHROMOSOME MUTATION Why is the mutation rate for a given gene inconsistent?
- Mutation rates can be increased by the presence of mutagens.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Mutation rates for a given gene are constant.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Mutation rates vary substantially between species.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Mutation rates vary substantially between different strains of the same species.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION HOT SPOTS
- HOT SPOTS: Locations within the chromosome that are more susceptible to mutation.
- L8 - GENE & CHROMOSOME MUTATION What are 2 reasons why some genes will mutate faster than other genes in the same individual?
- 1. Some genes are larger than others, providing more space for mutations. 2. Some genes are located at hot spots on the chromosome.
- L8 - GENE & CHROMOSOME MUTATION MUTATION FREQUENCY
- MUTATION FREQUENCY: (number of mutant alleles of a specific gene) divided by (total number of genes in a population)
- L8 - GENE & CHROMOSOME MUTATION What are the 2 classes of gene mutation in multicellular eukaryotes?
- 1. Somatic 2. Germinal
- L8 - GENE & CHROMOSOME MUTATION SOMATIC MUTATION
- Mutation in vegetative cells involved in aging/cancers, not passed on to future generations.
- L8 - GENE & CHROMOSOME MUTATION GERMINAL MUTATION
- GERMINAL MUTATION: Source of new alleles that can be passed on to future generations.
- L8 - GENE & CHROMOSOME MUTATION If 1 million bacteria were plated and 10 were mutant, what would be the mutation frequency?
- 10/1,000,000 = 1 in 100,000 = 10-5
- L8 - GENE & CHROMOSOME MUTATION What type of mutation creates patches of mutated cells?
- Somatic
- L8 - GENE & CHROMOSOME MUTATION GENETIC MOSAIC
- GENETIC MOSAIC: Organism composed of patches of mutated cells.
- L8 - GENE & CHROMOSOME MUTATION What are the three types of phenotypically expressed mutations?
- 1. Loss-of-function 2. Gain-of-function 3. Silent
- L8 - GENE & CHROMOSOME MUTATION What is the inheritance character of loss-of-function mutations?
- Recessive/Incompletely dominant
- L8 - GENE & CHROMOSOME MUTATION What is the inheritance character of gain-of-function mutations?
- Dominant/Codominant
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Gain-of-function mutations are rare.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION What are the 2 instances where silent mutations may cause phenotypic changes?
- 1. Disrupts RNA processing 2. Disrupts gene expression
- L8 - GENE & CHROMOSOME MUTATION RADIATION BREEDING
- RADIATION BREEDING: The practice of exposing crops to gamma radiation to produce beneficial mutations.
- L8 - GENE & CHROMOSOME MUTATION What is an example of a loss-of-function mutation?
- "Ruby red" grapefruit
- L8 - GENE & CHROMOSOME MUTATION How many crop varieties have been developed by radiation mutation?
- Over 2,000.
- L8 - GENE & CHROMOSOME MUTATION What type of mutation causes cancer?
- Somatic
- L8 - GENE & CHROMOSOME MUTATION What 3 objectives must cancerous cells meet before they can take over a body?
- 1. Acquire rapid cell division (forms a tumor) 2. Acquire a new blood supply 3. Acquire ability to invade other tissues (metastasis)
- L8 - GENE & CHROMOSOME MUTATION METASTASIS
- METASTASIS: The ability of cancerous cells to move to and invade other tissues.
- L8 - GENE & CHROMOSOME MUTATION PROTO-ONCOGENES
- PROTO-ONCOGENES: Turn on cell growth/division, normal developmental function genes.
- L8 - GENE & CHROMOSOME MUTATION TUMOR SUPPRESSOR GENES
- TUMOR SUPPRESSOR GENES: Suppress cell growth/division.
- L8 - GENE & CHROMOSOME MUTATION What are the 2 possible results of a 2nd mutation in a gene that is already mutant?
- 1. Dead/malfunctioning cell (aging) 2. Cancerous cell
- L8 - GENE & CHROMOSOME MUTATION ONCOGENE
- ONCOGENE: Mutant proto-oncogene whose dominant path is to become a cancer cell and whose recessive path is to acquire a second mutation.
- L8 - GENE & CHROMOSOME MUTATION In what 4 genes can mutations lead to cancer?
- 1. Proto-oncogenes 2. Tumor suppressor genes 3. Mutator genes 4. Telomerase genes
- L8 - GENE & CHROMOSOME MUTATION How does a mutation in a mutator gene lead to cancer?
- Mutator genes are involved in DNA repair and mutations in these genes permit higher levels of mutation in general.
- L8 - GENE & CHROMOSOME MUTATION How does a mutation in a telomerase gene lead to cancer?
- Leads to unlimited cell division (immortal cells).
- L8 - GENE & CHROMOSOME MUTATION What is the minimum number of mutations needed for an individual to develop retinoblastoma?
- 2 (thus, most common in children)
- L8 - GENE & CHROMOSOME MUTATION What is the minimum number of mutations needed for an individual to develop colon cancer?
- 4-5 (thus, most common in adults).
- L8 - GENE & CHROMOSOME MUTATION What is the minimum number of mutations required for an individual to develop small-cell lung cancer?
- 10-15 (thus, most common in adults with high exposures to mutagens [smokers]).
- L8 - GENE & CHROMOSOME MUTATION What are the 4 ways mutations can alter chromosome shape?
- 1. Deficiency (deletion) 2. Duplication 3. Inversion 4. Translocation
- L8 - GENE & CHROMOSOME MUTATION DEFICIENCY MUTATION
- DEFICIENCY MUTATION: Loss of chromosomal segment.
- L8 - GENE & CHROMOSOME MUTATION DUPLICATION MUTATION
- DUPLICATION MUTATION: Repetition of chromosomal segment.
- L8 - GENE & CHROMOSOME MUTATION INVERSION MUTATION
- INVERSION MUTATION: Change in gene direction along chromosome.
- L8 - GENE & CHROMOSOME MUTATION TRANSLOCATION MUTATION
- TRANSLOCATION MUTATION: Segment of one chromosome attaches to another chromosome.
- L8 - GENE & CHROMOSOME MUTATION What are the 2 types of translocation mutations?
- 1. Simple (one-way) 2. Reciprocal (exchange)
- L8 - GENE & CHROMOSOME MUTATION What are 3 ways chromosomal mutations affect gene expression?
- 1. Gene breaks 2. Movement to regulatory sequence 3. Movement to heterochromatic sequence
- L8 - GENE & CHROMOSOME MUTATION HETEROCHROMATIC REGION
- HETEROCHROMATIC REGION: Compact, gene-poor chromosomal region.
- L8 - GENE & CHROMOSOME MUTATION POSITION EFFECT
- POSITION EFFECT: When a gene's expression is altered due to movement from one region of the chromosome to another.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Duplication mutations are always detrimental.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION How can duplication mutations benefit gene evolution?
- Provides an opportunity for gene evolution without loss of the original product.
- L8 - GENE & CHROMOSOME MUTATION What happened to the lysozyme gene in langur monkeys?
- Promoter mutations caused lysozyme gene to be expressed in the stomach instead of the tears, allowing them to digest cellulose-eating bacteria but causing more eye infections.
- L8 - GENE & CHROMOSOME MUTATION What happened to the lysozyme gene in ruminants?
- Duplication mutations caused the lysozyme gene to express in both the eyes and the stomach, preventing eye infections and allowing digestion of cellulose-eating bacteria.
- L8 - GENE & CHROMOSOME MUTATION MONOPLOID NUMBER (X)
- MONOPLOID NUMBER (X): # of chromosome sets not including duplicated/homologous chromosomes. Can be different from haploid number (n).
- L8 - GENE & CHROMOSOME MUTATION What is an organism where the monoploid number (X) differs from the haploid number (n)?
- Wheat (6X, 2n)
- L8 - GENE & CHROMOSOME MUTATION What is an organism where the monoploid number (X) is identical to the haploid number (n)?
- Humans (2X, 2n)
- L8 - GENE & CHROMOSOME MUTATION What are the names for each monoploid number from 1X to 6X?
- 1X: monoploid 2X: diploid 3X: triploid 4X: tetraploid 5X: pentaploid 6X: hexaploid
- L8 - GENE & CHROMOSOME MUTATION Any organism that has a monoploid number greater than 2X is what?
- Polyploid
- L8 - GENE & CHROMOSOME MUTATION What are 4 examples of monoploids (1X)?
- 1. Male bees 2. Male wasps 3. Male ants 4. Artificially derived plants
- L8 - GENE & CHROMOSOME MUTATION What are the 2 types of polyploids?
- 1. Autopolyploids 2. Allopolyploids
- L8 - GENE & CHROMOSOME MUTATION AUTOPOLYPLOID
- AUTOPOLYPLOID: Multiple chromosome sets from 1 species.
- L8 - GENE & CHROMOSOME MUTATION ALLOPOLYPLOID
- ALLOPOLYPLOID: Multiple chromosome sets from different species.
- L8 - GENE & CHROMOSOME MUTATION What is an example of an allopolyploid?
- Triticale (wheat X rye)
- L8 - GENE & CHROMOSOME MUTATION In order for an allopolyploid to form, the chromosome sets from 2 different species must be what?
- Homologous
- L8 - GENE & CHROMOSOME MUTATION TRIPLOID
- TRIPLOID: Result of tetraploid X diploid cross, sterile due to pairing problems during meiosis.
- L8 - GENE & CHROMOSOME MUTATION What are 2 examples of triploids?
- 1. Bananas 2. Seedless watermelons
- L8 - GENE & CHROMOSOME MUTATION What are 5 examples of polyploidy in animals?
- 1. Flatworms 2. Leeches 3. Brine shrimp 4. Amphibians 5. Fish
- L8 - GENE & CHROMOSOME MUTATION Why are Salmonidae (salmon and trout) thought to be polyploids?
- Salmonidae contain twice as much DNA as closely related fish.
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Polyploidy is rarer in plants than in animals.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION ANEUPLOIDY
- ANEUPLOIDY: Chromosome number differs from wild-type by part of a chromosome set.
- L8 - GENE & CHROMOSOME MUTATION MONOSOMIC
- MONOSOMIC: 2n-1
- L8 - GENE & CHROMOSOME MUTATION TRISOMIC
- TRISOMIC: 2n+1
- L8 - GENE & CHROMOSOME MUTATION NULLISOMIC
- NULLISOMIC: 2n-2
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Aneuploidy is generally deleterious.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION What causes aneuploidy?
- Nondisjunction during meiosis/mitosis.
- L8 - GENE & CHROMOSOME MUTATION DISJUNCTION
- DISJUNCTION: Normal separation of chromosomes to opposite poles during division.
- L8 - GENE & CHROMOSOME MUTATION NONDISJUNCTION (meiosis)
- NONDISJUNCTION (meiosis): Homologous chromosomes failing to separate.
- L8 - GENE & CHROMOSOME MUTATION NONDISJUNCTION (mitosis)
- NONDISJUNCTION (mitosis): Sister chromatids failing to separate.
- L8 - GENE & CHROMOSOME MUTATION What is an example of an aneuploidy disease in humans?
- Down syndrome.
- L8 - GENE & CHROMOSOME MUTATION What causes Down syndrome?
- Trisomy (2n+1), extra copy of autosome #21.
- L8 - GENE & CHROMOSOME MUTATION What are 4 phenotypes of Down syndrome?
- 1. Mental retardation 2. Broad, flat face 3. Short stature 4. Heart problems
- L8 - GENE & CHROMOSOME MUTATION 1 in how many children born will have Down syndrome?
- 1 in 600-700 (most common human aneuploid).
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: The chance of nondisjunction causing Down syndrome increases with the mother's age.
- TRUE
- L8 - GENE & CHROMOSOME MUTATION TRUE/FALSE: Most aneuploids survive to birth.
- FALSE
- L8 - GENE & CHROMOSOME MUTATION How many cases of Down syndrome are linked to nondisjunction in the father?
- 5%
- L8 - GENE & CHROMOSOME MUTATION SOMATIC ANEUPLOID
- SOMATIC ANEUPLOID: Aneuploidy occurring in early development mitosis.
- L8 - GENE & CHROMOSOME MUTATION GYNANDROMORPH
- GYNANDROMORPH: Genetic mosaic created by somatic aneuploidy.
- L8 - GENE & CHROMOSOME MUTATION What is an example of a somatic aneuploid?
- Io Moth (50% of males and 50% of females)
- L9 - GENE REGULATION What are 5 potential carbon sources for bacteria?
- 1. Glucose 2. Lactose 3. Maltose 4. Galactose 5. Xylose
- L9 - GENE REGULATION CATABOLISM
- CATABOLISM: Metabolic pathways that break down molecules into energy.
- L9 - GENE REGULATION How do bacteria prevent themselves from producing the enzymes for potential carbon sources until the source is actually present?
- Gene regulation.
- L9 - GENE REGULATION LAC OPERON
- LAC OPERON: Negative control expressed only in the presence of lactose.
- L9 - GENE REGULATION Lactose serves as what for the Lac operon?
- Inducer
- L9 - GENE REGULATION OPERON
- OPERON: Bacterial gene that encodes several products (polycistronic).
- L9 - GENE REGULATION POLYCISTRONIC
- POLYCISTRONIC: Gene that encodes several products.
- L9 - GENE REGULATION What 3 products does the Lac operon encode?
- 1. B-galatosidase (Z) 2. Permease (Y) 3. Transacetylase (A)
- L9 - GENE REGULATION What is the function of B-galatosidase (Z) in bacteria?
- B-galatosidase cleaves lactose into glucose/galactose.
- L9 - GENE REGULATION What is the function of permease (Y) in bacteria?
- Permease transports lactose into the bacterial cell.
- L9 - GENE REGULATION What is the lactose-related function of transacetylase (A) in bacteria?
- Transacetylase (A) has no lactose-related function.
- L9 - GENE REGULATION I GENE
- I GENE: Constitutively expresses Lac repressor.
- L9 - GENE REGULATION TRANS-ACTING ELEMENT
- TRANS-ACTING ELEMENT: Product of a gene that affects another gene.
- L9 - GENE REGULATION CIS-ACTING ELEMENT
- CIS-ACTING ELEMENT: DNA sequence that affects adjacent genes.
- L9 - GENE REGULATION OPERATOR (Lac)
- OPERATOR (Lac): Portion of the Lac operon that binds to the I-gene-produced repressor.
- L9 - GENE REGULATION IPTG
- IPTG: Synthetic Lac operon inducer that mimics lactose structure, binding to the I-produced repressor but not cleaved.
- L9 - GENE REGULATION TRUE/FALSE: IPTG concentration does not remain constant after binding to the I-produced Lac repressor.
- FALSE
- L9 - GENE REGULATION What happens if the operator of the Lac operon can no longer bind to the I-produced repressor?
- Constitutive Lac operon expression.
- L9 - GENE REGULATION Oc MUTATION
- Oc MUTATION: Operator sequence changes.
- L9 - GENE REGULATION I- MUTATION
- I- MUTATION: Changes I-produced repressor conformation so that it no longer binds to Lac operon operator.
- L9 - GENE REGULATION What happens due to I- mutation expression?
- Constitutive expression of the Lac operon.
- L9 - GENE REGULATION TRUE/FALSE: I- is dominant.
- FALSE
- L9 - GENE REGULATION Is MUTATION
- Is MUTATION: Changes I-produced repressor conformation so that it no longer binds to the Lac operon inducer (lactose).
- L9 - GENE REGULATION What happens due to Is mutation expression?
- Lac operon is not expressed.
- L9 - GENE REGULATION TRUE/FALSE: Is is dominant.
- TRUE
- L9 - GENE REGULATION How would you determine if the Is mutation is dominant or recessive?
- Perform a cross with complementation using a partial diploid where both alleles are present in the cell.
- L9 - GENE REGULATION TRUE/FALSE: It takes fewer resources for a bacteria to utilize a glucose growth medium than a lactose growth medium.
- TRUE
- L9 - GENE REGULATION What happens if a bacterium with a Lac operon is placed on a growth medium with both lactose and glucose?
- Lac operon does not turn on; bacterium utilizes glucose.
- L9 - GENE REGULATION Glucose catabolism by bacteria inhibits the formation of what?
- cAMP (cyclic adenosine monophosphate).
- L9 - GENE REGULATION If you increase the amount of glucose in a bacterial growth medium, the amount of cAMP produced by the bacteria does what?
- cAMP production decreases.
- L9 - GENE REGULATION What part of the Lac operon does cAMP bind to?
- CAP (catabolite activator protein).
- L9 - GENE REGULATION CAP increases the the binding of what to the Lac operon's promoter?
- RNA polymerase.
- L9 - GENE REGULATION TRUE/FALSE: An increase in CAP leads to an increase in Lac operon expression.
- TRUE
- L9 - GENE REGULATION What kind of control is the cAMP/CAP complex?
- Positive (required for activation).
- L9 - GENE REGULATION What are 2 gene products of a bacterium in a high glucose growth medium?
- 1. Inactive adenylate cyclase. 2. No cAMP.
- L9 - GENE REGULATION What are 2 gene products of a bacterium in a low glucose growth medium?
- 1. Active adenylate cyclase. 2. cAMP.
- L9 - GENE REGULATION What is the state of Lac mRNA under: glucose, no lactose?
- No Lac mRNA produced.
- L9 - GENE REGULATION What is the state of Lac mRNA under: glucose, lactose?
- Little Lac mRNA produced.
- L9 - GENE REGULATION What is the state of Lac mRNA under: no glucose, lactose?
- Abunt Lac mRNA produced.
- L9 - GENE REGULATION NEGATIVE CONTROL
- NEGATIVE CONTROL: Prevents expression.
- L9 - GENE REGULATION POSITIVE CONTROL
- POSITIVE CONTROL: Enhances expression.
- L9 - GENE REGULATION INDUCIBLE SYSTEM
- INDUCIBLE SYSTEM: Gene is normally off.
- L9 - GENE REGULATION REPRESSIBLE SYSTEM
- REPRESSIBLE SYSTEM: Gene is normally on.
- L9 - GENE REGULATION List examples of the 3 following components in the Lac operon: 1. Inducible system 2. Positive control 3. Negative control
- 1. Lac operon 2. cAMP/CAP 3. I gene
- L9 - GENE REGULATION What is an example of a repressible system?
- trp operon
- L9 - GENE REGULATION On average, how many cis-acting elements exist in human genes?
- 5
- L9 - GENE REGULATION What is the highest number of cis-acting elements possible in a human gene?
- 20
- L9 - GENE REGULATION Developmental genes are regulated by what?
- Regulatory cascades
- L9 - GENE REGULATION MASTER SWITCH
- MASTER SWITCH: Gene that commits development down just one of many paths.
- L9 - GENE REGULATION What is a developmental gene example governed by a master switch?
- Sex determination
- L9 - GENE REGULATION Is the Lac operon model system prokaryotic or eukaryotic?
- Prokaryotic
- L9 - GENE REGULATION How many RNA polymerases do eukaryotes have?
- 3
- L9 - GENE REGULATION In eukaryotes, what RNA polymerase transcribes all mRNA?
- RNA Polymerase II
- L9 - GENE REGULATION To initiate transcription, what must RNA polymerase bind to?
- Promoter
- L9 - GENE REGULATION TRUE/FALSE: In eukaryotic gene regulation, silencers/enhancers work like volume dials, not light switches.
- TRUE
- L9 - GENE REGULATION ENHANCER
- ENHANCER: Enhances RNA polymerase binding.
- L9 - GENE REGULATION SILENCER
- SILENCER: Inhibits RNA polymerase binding.
- L9 - GENE REGULATION TRUE/FALSE: Enhancers/Silencers cannot be tissue-specific.
- FALSE
- L9 - GENE REGULATION TRUE/FALSE: Enhancers/Silencers can be located upstream or downstream, near to or far from the core promoter.
- TRUE
- L9 - GENE REGULATION CORE PROMOTER
- CORE PROMOTER: Transcription start site, where RNA polymerase binds to the DNA.
- L9 - GENE REGULATION PROMOTER PROXIMAL ELEMENTS
- PROMOTER PROXIMAL ELEMENTS: 1. CCAAT box 2. GC-rich region
- L9 - GENE REGULATION What 3 sequences are needed to initiate transcription?
- 1. Core promoter 2. CCAAT box 3. GC-rich region
- L9 - GENE REGULATION How far upstream from the TATA box is the core promoter?
- 30 BP
- L9 - GENE REGULATION How far upstream from the core promoter are the promoter proximal elements?
- 100-200 BP
- L9 - GENE REGULATION GLOBAL GENE CONTROL
- GLOBAL GENE CONTROL: Cells in one part of the body can control gene expression in other cells throughout the body (eukaryotes).
- L9 - GENE REGULATION What is an example of global gene control in humans?
- Endocrine system
- L9 - GENE REGULATION What are 5 functions of the endocrine organs?
- 1. Sex determination 2. Fight/flight response 3. Metabolic rate 4. Sugar regulation 5. Growth
- L9 - GENE REGULATION What kind of hormones does the endocrine system produce?
- Steroid
- L9 - GENE REGULATION What are the 5 steps of global gene control by the human endocrine system?
- 1. Endocrine cell's genes order production of enzymes 2. Cell #1's enzymes create steroid hormones 3. Steroid hormones travel through blood 4. Steroid hormones encounter receptor protein on cell #2 5. Steroid hormones bind to enhancers in cell #2's genes
- L9 - GENE REGULATION A hormone-responsive enhancer represents what kind of system and what kind of control?
- Inducible system, positive control.
- L9 - GENE REGULATION During what 5 processes can gene products be regulated?
- 1. DNA transcription 2. Splicing 3. Subcellular localization 4. Subunit complex formation 5. Protein modification
- L9 - GENE REGULATION What 4 protein-transitional products can be regulated?
- 1. Primary DNA transcript 2. mRNA 3. Polypeptide 4. Protein (inactive)
- L9 - GENE REGULATION What sex is XX in fruit flies? In humans?
- Both female
- L9 - GENE REGULATION What sex is XY in fruit flys? In humans?
- Both male
- L9 - GENE REGULATION What sex is XXY in fruit flies? In humans?
- Fruit flies: female Humans: male
- L9 - GENE REGULATION What sex is XO in fruit flies? In humans?
- Fruit flies: male Humans: female
- L9 - GENE REGULATION Different outcomes from what 2 sex chromosomes show sex is determined by different mechanisms in fruit flies and humans?
- XXY, XO
- L9 - GENE REGULATION For fruit flies, an X:A ratio of 1.0 results in what sex?
- Female
- L9 - GENE REGULATION For fruit flies, an X:A ratio of 0.5 results in what sex?
- Male
- L9 - GENE REGULATION DIMER
- DIMER: Quaternary combination structure of 2 polypeptides.
- L9 - GENE REGULATION In fruit flies, how many genes encode for sex-determining transcription factors?
- 2
- L9 - GENE REGULATION In fruit flies, what does the X chromosome have that an autosomal chromosome doesn't?
- Functional DNA binding domain
- L9 - GENE REGULATION In fruit flies, what does the Sxl gene encode?
- Female-specific splicing
- L9 - GENE REGULATION In fruit flies, what does the tra gene encode?
- Control of dsx gene RNA splicing.
- L9 - GENE REGULATION The dsx gene in fruit flies is an example of what kind of system and what kind of control?
- Repressible system, negative control?
- L9 - GENE REGULATION For fruit flies, what does the dsx gene repress in females? In males?
- Females: male-specific structural genes repressed. Males: female-specific structural genes repressed.
- L9 - GENE REGULATION Why does the early promoter of the Sxl gene turn on in female fruit flies, but not in males?
- Many active transcription factors in females.
- L9 - GENE REGULATION TRUE/FALSE: The Sxl gene in fruit flies is a master switch.
- TRUE
- L9 - GENE REGULATION In fruit flies, what are the 5 steps of the female-specific regulatory cascade?
- 1. Sxl gene ON 2. tra gene ON 3. dsx gene causes female-specific mRNA splicing 4. dsx-F protein produced 5. Male-specific genes repressed
- L9 - GENE REGULATION In fruit flies, what are the 5 steps of the male-specific regulatory cascade?
- 1. Sxl gene OFF 2. tra gene OFF 3. dsx gene causes male-specific mRNA splicing 4. dsx-M protein produced 5. Female-specific genes repressed
- L9 - GENE REGULATION In fruit flies, a null mutation of Sxl results in what sex?
- Male
- L9 - GENE REGULATION In fruit flies, a null mutation of tra results in what sex?
- Male
- L9 - GENE REGULATION TRUE/FALSE: Male is the default sex of fruit flies.
- TRUE
- L9 - GENE REGULATION TRUE/FALSE: Male is the default sex of humans.
- FALSE
- L9 - GENE REGULATION In fruit flies, a null mutation of dsx results in what sex?
- Male AND female (hermaphroditic)
- L9 - GENE REGULATION What determines sex in mammals?
- Presence/Absence of the Y chromosome.
- L9 - GENE REGULATION What are the 2 characteristics of sex determination in mammals?
- 1. Non-autonomous 2. Global
- L9 - GENE REGULATION What are the 2 characteristics of sex determination in fruit flies?
- 1. Autonomous 2. Every cell
- L9 - GENE REGULATION What drives the appearance of secondary sexual phenotypes in mammals?
- Presence/Absence of testes.
- L9 - GENE REGULATION In mammals, gonads form within how many months of conception?
- 2
- L9 - GENE REGULATION List the 4 steps that result in the enhancement of male-specific gene expression in mammals.
- 1. Y chromosome present, testes form. 2. Testes secrete testosterone (steroid). 3. Testosterone binds to androgen-receptors in all body cells (global). 4. Testosterone-binding androgen receptors act as transcription factors which enhance male-specific gene expression.
- L9 - GENE REGULATION What happens due to a null mutation in the androgen-receptor gene in mammals?
- Tfm (testicular feminization syndrome): XY female with female secondary phenotypes but testes instead of ovaries.
- L9 - GENE REGULATION TRUE/FALSE: If a woman is exposed to excess amounts of testosterone, or if she produces too much testosterone from her own body, she will become male.
- FALSE
- L9 - GENE REGULATION What gene drives testes formation?
- SRY gene
- L9 - GENE REGULATION How was the SRY gene identified?
- Studies of sex reversal (XX males).
- L9 - GENE REGULATION SEX REVERSAL
- SEX REVERSAL: XX males, caused by translocation of Y chromosome onto X chromosome.
- L9 - GENE REGULATION What is the sex-determining master switch in mammals?
- SRY gene
- L9 - GENE REGULATION What gene was proved to exist when XX male mice were cloned from female mice?
- SRY gene
- L10 - GENETIC ENGINEERING In what year was modern biotechnology born?
- 1972
- L10 - GENETIC ENGINEERING In what year was recombinant human insulin first produced?
- 1978
- L10 - GENETIC ENGINEERING RECOMBINANT DNA
- RECOMBINANT DNA: DNA resulting from combinations of 2 source DNAs.
- L10 - GENETIC ENGINEERING What are 5 processes that result in recombinant DNA?
- 1. Crossing-over during meiosis 2. Chromosomal rearrangement 3. Development of immune response cells 4. Viral/Transposon activity 5. Modern molecular techniques
- L10 - GENETIC ENGINEERING CLONING
- CLONING: Creation of genetically identical copies of DNA molecules, cells, or whole organisms?
- L10 - GENETIC ENGINEERING What are 3 examples of processes that result in clone creation?
- 1. Bacterial replication 2. Development of identical twins 3. Plant propagation from cuttings
- L10 - GENETIC ENGINEERING GENETIC ENGINEERING
- GENETIC ENGINEERING: Using cloning and DNA recombination to modify a gene, cell, or organism.
- L10 - GENETIC ENGINEERING What are the 4 basic tools used for the creation of recombinant DNA?
- 1. VECTOR (plasmids) 2. DNA CUTTERS (restriction endonucleases) 3. DNA CONNECTORS (DNA ligase) 4. DNA CLONE AMPLIFIER (E. coli)
- L10 - GENETIC ENGINEERING PLASMID
- PLASMID: Circular DNA molecule.
- L10 - GENETIC ENGINEERING What are the 2 types of plasmids and how many copies of each can exist in a cell?
- 1. STRINGENT (1-2 copies) 2. RELAXED (100s of copies)
- L10 - GENETIC ENGINEERING What do bacteria use plasmids for?
- Genetic exchanges
- L10 - GENETIC ENGINEERING What are the 4 steps used to prepare a plasmid for use as a vector?
- 1. Make smaller (3 Kb) 2. Add selectable marker (ampicillin resistance) 3. Select polylinker or multiple cloning site 4. Add scorable marker (optional - LacZ gene)
- L10 - GENETIC ENGINEERING What do white and blue markers indicate on a vector plasmid?
- WHITE: inserted DNA BLUE: failed to insert DNA
- L10 - GENETIC ENGINEERING What do bacteria use restriction endonucleases for?
- Defense against viruses.
- L10 - GENETIC ENGINEERING What does the "endonuclease" in restriction endonuclease refer to?
- ENDONUCLEASE: Because it cleaves DNA internally.
- L10 - GENETIC ENGINEERING How does a bacterium keep restriction endonuclease from cleaving its own chromosome?
- Bacterial chromosomes are methylated (marked).
- L10 - GENETIC ENGINEERING What is the naming convention for restriction endonucleases?
- Bacteria, strain, order of discovery Ex. HinddIII Hind: bacteria d: strain III: 3rd endonuclease discovered
- L10 - GENETIC ENGINEERING What are the 4 types of RE recognition sequences?
- 4, 5, 6, 8
- L10 - GENETIC ENGINEERING TRUE/FALSE: Larger recognition sites for REs are found more often than smaller sites.
- FALSE
- L10 - GENETIC ENGINEERING What are 3 examples of REs and what does each one produce after cleaving?
- 1. HaeIII (blunt ends) 2. HindIII (5' overhangs) 3. PstI (3' overhangs)
- L10 - GENETIC ENGINEERING What do bacteria use DNA ligase for?
- Connection of newly synthesized DNA fragments, DNA repair.
- L10 - GENETIC ENGINEERING In genetic engineering, what is the most commonly used DNA ligase?
- T4
- L10 - GENETIC ENGINEERING What are the 4 steps used to join DNA fragments into recombinant molecules?
- 1. Cut DNA from 2 sources with same RE 2. Denature ends of each DNA and mix 3. Permit annealing of DNA ends 4. Use DNA ligase to form new phosphodiester bonds between resulting fragments
- L10 - GENETIC ENGINEERING Why is DNA ligase needed to form new phosphodiester bonds between new recombinant molecules?
- The new molecules are not covalently linked yet.
- L10 - GENETIC ENGINEERING After recombinant molecules have been created, what 3 further steps should be followed to create an ample supply of the recombinant DNA?
- 1. Ligate recombinant DNA to a plasmid vector. 2. Transform E. coli bacteria by placing plasmid vector in their environment. 3. Grow E. coli to amplify recombinant DNA.
- L10 - GENETIC ENGINEERING What process can create DNA clones without host cells?
- Polymerase Chain Reaction (PCR).