Term
| What is polycistronic mRNA? |
|
Definition
| An mRNA that has similar clustered genes |
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|
Term
| What is monocistronic mRNA? |
|
Definition
| An mRNA that has only one gene |
|
|
Term
| What type of mRNA is present in prokaryotes? |
|
Definition
|
|
Term
| What type of mRNA is present in eukaryotes? |
|
Definition
|
|
Term
| What is the general sequence of an mRNA? |
|
Definition
| Cap, Start codon, Coding sequence, Stop codon, Poly A tail |
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|
Term
| What is the advantage of having a polycistronic mRNA? |
|
Definition
| Similar proteins can be transcribed together |
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|
Term
| What is the disadvantage of having a polycistronic mRNA? |
|
Definition
| If a malfunction occurs in the transcription promoter then all proteins are not transcribed |
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|
Term
| What is the advantage of having a monocistronic mRNA? |
|
Definition
| If a malfunction occurs in the transcription promoter then one only one protein is not transcribed |
|
|
Term
| What is the disadvantage of having a monocistronic mRNA? |
|
Definition
| Proteins have to each be transcribed seperately |
|
|
Term
| How many different RNA polymerases do eukaryotes have? |
|
Definition
|
|
Term
| What does RNA polymerase I transcribe? |
|
Definition
|
|
Term
| What does RNA polymerase II transcribe? |
|
Definition
|
|
Term
| What does RNA polymerase III transcribe? |
|
Definition
| tRNA, 5s rRNA and other smaller RNA's |
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|
Term
|
Definition
|
|
Term
| What does the TATA-box bind? |
|
Definition
|
|
Term
|
Definition
| Recruit RNA polymerase II and other transcription factors |
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|
Term
|
Definition
|
|
Term
| Where does transcription end? |
|
Definition
| 10-35nt downstream of the AAUAAA seqeunce |
|
|
Term
| How do endonucleases relate to transcription? |
|
Definition
| They can release the DNA from RNA polymerase |
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|
Term
| What is the equivalent of the TATA-box in prokaryotes? |
|
Definition
|
|
Term
| Give three examples of changing gene expression patterns? |
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Definition
| Cancer, Tissue differentiation and development |
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Term
| What is the name of the machinery that removed introns? |
|
Definition
|
|
Term
| What is the purpose of the splice sites of introns? |
|
Definition
| Recruits the spilcesosome so the introns can be spliced out |
|
|
Term
| What is the effect of an intron mutation? |
|
Definition
| Does not affect coding sequence but may effect splicing |
|
|
Term
| What is the effect of an exon mutation? |
|
Definition
| Affects the coding sequence |
|
|
Term
| What two things are added to mRNA after cplicing? |
|
Definition
| The cap and the poly a tail |
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|
Term
|
Definition
| The addition of the cap to the mRNA |
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|
Term
|
Definition
| The addition of the poly A tail |
|
|
Term
| What does the small ribosomal subunit do? |
|
Definition
| Finds the reading frame of the DNA |
|
|
Term
| What does the large ribosomal subunit do? |
|
Definition
| Houses the protein synthetic peptidyl transferase centre |
|
|
Term
| How is the open reading frame in bacterial translation identified? |
|
Definition
| By the Shine-Dalgarno sequence |
|
|
Term
| What is the advantage of using the Shine-Dalgarno sequence to translated bacterial mRNA? |
|
Definition
| All the polycistronic proteins can be transcribed seperately but also at the same time |
|
|
Term
| When the small ribosomal subunit has recognised the open reading frame it does what? |
|
Definition
| Binds the CAP protein to the first AUG |
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|
Term
| What is the Kozak consensus? |
|
Definition
| The most frequently found sequence before the AUG |
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|
Term
| What does coupled mean in reference to transcription and translation? |
|
Definition
| Translation can affect transcription |
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|
Term
| What does uncoupled mean in reference to transcription and translation? |
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Definition
| Translation can not affect transcription |
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|
Term
| Prokaryotes undergo _______ translation and transcription? |
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Definition
|
|
Term
| Eukaryotes undergo _______ translation and transcription? |
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Definition
|
|
Term
| What is the limiting factor in the trp operon? |
|
Definition
| The presence of tryptophan |
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|
Term
| Which amino acid does the code AUG code for? |
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Definition
|
|
Term
| Who conducted many experiments into inheritance? |
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Definition
|
|
Term
| How did Mendel carry out his inheritance studies? |
|
Definition
|
|
Term
| What is a monohybrid cross? |
|
Definition
| A genetic cross between two individuals that differ in one trait |
|
|
Term
| What is Mendels first law? |
|
Definition
| The principle of segregation |
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|
Term
| Why is it unlikely that we have many single-gene traits in the human body? |
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Definition
| Large number of genes and environmental influence |
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|
Term
| What are the four single-gene traits? |
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Definition
| PTC tasting, albinism, white cats and wet/dry earwax |
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|
Term
| Which allele controls PTC tasting? |
|
Definition
|
|
Term
| Is albinism dominant, recessive or codominant? |
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Definition
|
|
Term
| How common is the dominant 'W' allele in white cats? |
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Definition
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|
Term
| Is wet ear wax dominant or recessive? |
|
Definition
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|
Term
| The cross of a homozygous dom and a homozygous rec will always yield what? |
|
Definition
|
|
Term
| Te cross of a heterzygous and a homozygous rec will yeild what? |
|
Definition
50% Heterzygous
50% Homozygous rec |
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|
Term
| What is Mendels second law? |
|
Definition
| The principle of independent assortment |
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|
Term
| What are the two approaches to working out genotypic ratios? |
|
Definition
| Forked Line and Punnet Square |
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|
Term
| How do you work out the probability of each allele? |
|
Definition
| Multipliying all the probability's of each parents together |
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Term
| What is continuous variation> |
|
Definition
| Phenotypes showing a large range of variation rather than discrete phenotypes |
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|
Term
| What are polygenic phenotypes? |
|
Definition
| Characteristics that are influenced by more than one gene |
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|
Term
| Give two examples of polygenic phenotypes? |
|
Definition
|
|
Term
| What is a complementation group? |
|
Definition
| A set of mutations on the same chromosome that fail to compliment each other when crossed |
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|
Term
| What are the two types of drosophila wing? |
|
Definition
|
|
Term
| Give an example of a complimentaton group? |
|
Definition
|
|
Term
| WHat are the four alleles for Drosophila wings? |
|
Definition
|
|
Term
| What two alleles create wrinkled wings? |
|
Definition
|
|
Term
| Why do the c and x alleles not affect Drosophila wings? |
|
Definition
| The enzymes they code for do not affetc protein too much and so the wings are the same |
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Term
| Why do the a and b alleles affect Drosophila wings? |
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Definition
| The enzymes they code for do affect the proteins to the extent that the wings become wrinkled |
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|
Term
| What is the classical geneticist definition of a gene? |
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Definition
| Sequence required for a biological function/charcteristic |
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|
Term
| What is the molecular geneticist definition of a gene? |
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Definition
| Nucleic acid sequence necessary to produce and mRNA transcript and ultimately a polypeptide |
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Term
| Name the five human autosomal recessive conditions? |
|
Definition
| Albinism, Phenylketoneuria, Tay-Sachs, Cystic Fibrosis and Sickle Cell Anemia |
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Term
|
Definition
|
|
Term
|
Definition
| Inability to metabolise phenylalanine |
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|
Term
|
Definition
| Neurodegeneration due to lack of NAH |
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|
Term
| What is cysytic fibrosis? |
|
Definition
| Thick mucus due to lack of CFTR |
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|
Term
| What is sickle-cell anemia? |
|
Definition
| Mutation in the beta-chain of hemoglobin |
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|
Term
| Name the five human autosomal dominant conditions? |
|
Definition
| Huntington's disease, Achondroplastic dwarfism, Polydactyly, Hypercholerterolemia and FASPS |
|
|
Term
| What is Huntington's disease? |
|
Definition
| Progressive brain disease |
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|
Term
| What is Achondroplastic dwarfism? |
|
Definition
| Failure to convert cartlidge to bone |
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|
Term
|
Definition
|
|
Term
| What is hypoercholesterolemia? |
|
Definition
| Removal of cholesterol from the blood, causes heart attacks |
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|
Term
|
Definition
|
|
Term
| What is a family pedigree? |
|
Definition
| A family tree of genetic disease |
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|
Term
| What are the features of an autosomal recessive pedigree? |
|
Definition
| Unaffected parents with affected offspring and effecting both males and females |
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|
Term
| What are the features of an autosomal dominant predigree? |
|
Definition
| Appear in each generation affecting 5-% of offspring, affecting both males and females |
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Term
|
Definition
| Inherited diseases from the X chromosome |
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|
Term
| Why are sex related illnesses more prominent in men? |
|
Definition
| They only have one X chromosome so a mutation will always affect them |
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|
Term
| What are the four sex linked recessive disorders? |
|
Definition
| Haemophillia, Muscular dystophies, Fragile-X-Syndrome and Deuteranopia |
|
|
Term
|
Definition
| Unable to form clotting blood (Absence of factor VIII) |
|
|
Term
| What is Muscular Dustrophie? |
|
Definition
|
|
Term
| What is Fragile-X-Synedrome? |
|
Definition
|
|
Term
|
Definition
| Red/Green colour blindness |
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|
Term
| What is an example of an X-Linked dominant disorder? |
|
Definition
| Hypophosphatemia (Vitamin D-resistance rickets) |
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|
Term
| Who do affected males pass on the dominant sex linked traits to? |
|
Definition
|
|
Term
|
Definition
| Traits that show up equally due to both alleles being equally domianant |
|
|
Term
| Give an example of a co-dominant trait? |
|
Definition
|
|
Term
| What is incomplete dominance? |
|
Definition
| Where the offspring resemble neither parent |
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|
Term
| Give an example of incomplete dominance? |
|
Definition
| Petal colour in snapdragons |
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|
Term
|
Definition
| The alleles affect unrelated characteristics |
|
|
Term
| Give two examples of pleiotrophy? |
|
Definition
| Manx phenotype in cats and Sickle-cell syndrome |
|
|
Term
| What happens in heterozygotic Manx cats? |
|
Definition
|
|
Term
| What happens in homozygous Manx cats? |
|
Definition
|
|
Term
|
Definition
| Where one allele modifies/masks another |
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|
Term
| Give two examples of epistasis? |
|
Definition
| Bombay phenotypes and adenine bosynthesis in yeast |
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|
Term
| What happens in homozygous recessive bombay pheotypes |
|
Definition
| They can't produce substance H so can't add sugars A or B so always have O blood group |
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|
Term
|
Definition
| How not all expected phenotypic ratios are always met |
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|
Term
|
Definition
| How not all genes are expressed due to lack of environmental influence |
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|
Term
| Name a disorder that is affected by penetrance and expressivity? |
|
Definition
|
|
Term
| What is the main environmental influence factor? |
|
Definition
|
|
Term
|
Definition
| The inheritance of two genes due to them being situated at close loci |
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|
Term
| What prevents sex linkage? |
|
Definition
| The formation of chiasmata between the two genes during meiosis |
|
|
Term
| What are the two ways we can track linkage and recombination? |
|
Definition
| Using SNP's and RFLP's or doing genetic crosses |
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|
Term
|
Definition
| Cross and homozygous wild type with a homzygous recessive. Then test the heterozygous with each of the traits |
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|
Term
| How would one go about using genetic crosses to test for 2 linked genes? |
|
Definition
|
|
Term
| What is the equation for recombination frequency? |
|
Definition
| Recombinance frequency = ( Number of recombinants/total progeny )X100 |
|
|
Term
| How many centimorgans apart are two loci? |
|
Definition
|
|
Term
| In humans how many base pars is one centimorgan? |
|
Definition
|
|
Term
| WHta can we do with genetic and physical chromosome maps? |
|
Definition
| Combine them to find out more information about chromosome biology |
|
|
Term
|
Definition
| Genes that are grouped on chromosomes in the same way across many species |
|
|
Term
| How can we define chromosomal rearrangements? |
|
Definition
| By looking at different synteny blocks across organisms |
|
|
Term
| What is reciprocal translocation? |
|
Definition
| Where two non-homologous chromosomes break and exchange information |
|
|
Term
| What causes Acute Myelogenous Leukaemia? |
|
Definition
| Translocations between chromsomes (8 and 21) and (15 and 17) |
|
|
Term
| What is chromosome fusion? |
|
Definition
| Where two telocentric chromosomes fuse to create of chromosome |
|
|
Term
| What is Robertsonian translocation? |
|
Definition
| Removal of the short arms of chromosomes and the recombination of the longer arms to form one chromosome |
|
|
Term
| how do translocations and fusions occur? |
|
Definition
|
|
Term
| How does a genome become more complex? |
|
Definition
|
|
Term
| What is unequal sister chromosome crossover? |
|
Definition
| Where the sister chromosomes do not line up correctly and so one recieves more genetic information over the crossover |
|
|
Term
| Name an organism that has recently undergone a genome duplication? |
|
Definition
|
|
Term
| What can occur during whole genome duplication? |
|
Definition
| Recombination that results in mass loss of genes |
|
|
Term
|
Definition
| Transcription factors that influence the development patterns of development genes |
|
|
Term
| If hox genes are not expressed in humans what is usually affected? |
|
Definition
|
|
Term
| How do hox genes affect hemoglobin development? |
|
Definition
| Originally creates fetal hemoglobin with a high affinity for oxygen which then changes into adult hemoglobin with a normal affinity for oxygen |
|
|
Term
|
Definition
| production of abnormal hemoglobin due to unbalanced production of globins |
|
|
Term
| What are the two types of Thalassemia? |
|
Definition
|
|
Term
| What are the results from alpha thalassemia? |
|
Definition
1 or 2 affected -> No effect
3 affeted -> Unstable oxygen dissociation
4 affected -> Still birth |
|
|
Term
| What are the results from beta thalassemia? |
|
Definition
1 affected -> No symptons
2 affected -> Death at 20 years due to heart failure |
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