Module 6: Genetics Evolution and Ecosystems Flashcards
What is Mutation?
Mutation is a change to nucleotides of DNA which could result in the formation of a non-functional protein.
What is Gene Mutation?
Gene mutation is a change to DNA base sequence.
What are more likely to cause mutations?
Mutagenic Agents: These work by intefering with DNA replicaion during transcription e.g
-High energy radiation (UV light),
-Ionizing radiation (Gamma rays and X rays)
-Chemicals (carcinogens such as mustard gas and cigarette smoke).
What is an operon?
A cluster of genes under the control of a promoter.
What structural detail of a polypeptide is altered by gene mutations.
– The sequence of amino acids/ primary structure
What is a frameshift?
Frameshift is the addition or deletion of a base resulting in the subsequent codons to be altered.
Original:TAC TTC AGG TGG
Mutation:TAC TCA GGT GG
What type of mutation is this?
Deletion
Original:TAC TTC AGG TGG
Mutation:TAC ATT CAG GTG G
What type of mutation is this?
Addition
Original:TAC TTC AGG TGG
Mutation:TAC ATC AGG TGG
What type of mutation is this?
Substitution
What do transcription factors do?
Transcription factors control the expression of genes by controlling which gene is turned on or off during transcription.
What mechanism controls production of lactase ?
Lac operon.
How it is possible for a mutation to have no effect on the protein produced from that gene
– If the mutation occurs in the intron
– More than one codon codes for an amino acid/the genetic code is degenerate
– Some amino acids won’t alter the shape of the protein
What are the 3 types of point mutations?
– Substitution
– Insertion
– Deletion
What does the statement “the genetic code is degenerate” mean?
This means that more than one codon can code for an amino acid so point(substitution) mutations may have no effect and a nrmal functioning protein can still be made
What is a nonsense mutation?
This is when the protein that is being coded for is abruptly put to a stop so the polypeptide is no longer coded for.
What is a promoter
This is a DNA sequence where RNA polymerase binds to
What is an Operator?
This a DNA sequence where the repressor protein binds to
What are Introns?
Inrons are sections of DNA that do not code for a protein
What is decomposition?
Decomposition is the break down of dead organic matter by bacteria (saprobionts)
What is nitrogen fixation?
Nitrogen fixation is when nitrogen in the air is converted into nitrogen in plants by the bacteria- rhizobium and azobacter.
What is nitrification?
Nitrification is when ammonia in plants are converted into nitrites by nitrozomas and then into nitrates by nitrobacters
What is denitrification?
Denitrification is when ammonium ion (nitrates) are turned into nitrogen in the air by denitrifying bacteria
What is a climax comunity?
A climax community is the dominant species formed after the pioneer species have died.
What is a pioneer community?
A species that arrive before the climax community hence they have less biodiversity.
How is an allele spread thoughout the population?
– Variation occurs within the popuation
– Organisms with alleles which give them characteristics most suited to their environment are more likely to survive and reproduce to give
a fertile offspring. Hence, they can pass on the advantageous allele.
– Selection pressure occurs so overtime, the frequency of the advantageous allele increases in the population
What is likely to cause variation within a population?
Mutation
What can result in the formation of a new species?
Gene mutation.
Selection pressure.
A change in the environment.
What are the advantages of using immobilised enzymes?
– Enzymes can be reused
– Enzymes remain active over a wider range of temperature
– The product is not contaminated by enzymes
What chemical is produced by plants in response to attack by pathogens?
– Callose
Whatare the properties of cellulose?
– High tensile strength
– Inflexible
– Insoluble in water
Steps of gel electrophoreis…
– Load the samples unto the agarose gel
– Apply voltage for a set time
– Stain the gel
– Photograph the gel
What precautions should be taken when preparing a bacterial culture in order to ensure that the procedure is aeseptic?
– Pass the bacterial culture bottle over flame
– Do not set the lid of the bacterial culture bottle on the sterilised surface
– Wash hands
– Wear gloves
– Use sterile equipment
– Disinfect surfaces
– Use a bunsen to create an upwards air flow
What are the precautions that should be taken when preparing a bacterial culture in order to ensure the procedure is aeseptic?
– Pass the bottle of the bacterial culture over flame
– Do not set the lid of the bacterial culture on the sterilised surface
– Was your hands
– Sterilise surface
– Use sterile equipment
– Disinfect surfaces
– Have a bunsen flame to create an upwards air flow
what are some advantages of using microorganimsms in the production of food?
– No ethical issues
– Rapid growth
– Non-seasonal
– Suitable for vegeterians
– Takes up little space
– Low costs because they work at low temperatures
Why is a cooling system necessary during fermentation?
– It prevents the enzymes from denaturing
– It inibits the growth of pathogenic bacteria
What is a method that can be used to determine the concentration of protein in a solution?
Biosensor
What is the name of the gene responsible for controlling body plan in multicellular organisms?
Homeobox gene
Outline how to use a colorimeter to determine the concentration of protein in a solution
– Zero the colorimeter
– Use known concentrations of protein solutions
– Plot a calibration curve
– Measure the absorbance of the unknown sample
– Compare with the calibration graph
What is species eveness?
The relative abundance of each species in an area.
Suggest a reason other than epistasis on why the phenotypic ratio might not be 9:3:3:1?
– Sex linkage
– Both genes are on the same chromosome
What ia an allele?
– An allele is a different version of a gene
What is a genotype?
The alleles an organism has
What is a phenotype?
– A characteristic an allele produces
