application to genetics Flashcards
explain what is meant by sequencing the human genome and describe the type of data that might be made available on line (3)
- order of nucleotides/bases in the DNA
- sanger sequencing
- descriptions of method used
- data/infromation would give loci/equences of individual genes
- coding for specific amino acids/ proteins
- descriptions of introns and exons
explain how the extra information provided by the 100000 genomes prohect might be used in medicine (3)
- next generation sequencing/NGS
- locate genes responsible for rare genetic disorder/cancers /mutate sequences
- by comparing the genomes of sufferers with (normal genome/large number of indivudals)
- predisposition to disease/diagnosis/undertanding casues of diseaes
- developing treatements/gene therapy
- used in prenatal diagnosis
describe how the scenario above with sharon that could get liver damage by taking a drug illustrates on possible benefical application and an ethical diallema of genome sequencing (3)
- sharon would find out if the drug would give her liver damge/ benefit is matching drugs to genetic make up of patient/personalised medication
- ethial dilemma is over rights of access to genomic infromation
- misuse of genetic information by employers/insurers
- wider implication on family health
- anxiety/distress caused by knowledge
- social discrimination
what are sticky ends (1)
- the have unpaired bases
- they have exposed bases
- they are single stranded DNA sections
Define the term plasmid (1)
ring of/circle of/loop of DNA (found in bacteria)
why is it important to ue the same enzyme to cut open the plasmid and the piece of DNA (1)
so that the cut ends (of the fragment and the plasmid) are complementary
Name the type of enzyme used to join the cut fragment into the plasmid (1)
- ligase
explain why intron are more useful to genetic fingerprinting than exons (2)
- introns are non coding/blocks of repeated nucleotides/exons code for proteins
- so there is more variablitiy/more unique to the individual/number of times that the blocks are repeated varies/STRS vary
give two features of DNa profiles lead to the identification of a suspect at a crime scene (1)
- same position and thickness of bands
Dna at crime scene is often found in very small quantities PCR enables analysis of these small samples of DNA State how PCR makes this possible (1)
- nakes multiple copies/ampliies DNA
the enzyme used in PCR has an important function during interphase in both mitois a and meiosis
name the enzymes used
and the enzymes function in interphase (2)
- DNA polymerse
- DNA replication
why are two different primers needed for the strand of DNA (1)
- different nucleotide sequence at each end /one primer for each strand of DNA
suggest why it is important to use primers which are specific to a vertain gene on each chromosome (1)
- enables/specific/the gene to be amplifies/to be copied / to be replicated
Suggest why it is necesdday to express the quantity of genes as a ratio after using PCR and Dna electrophoresis (2)
- does not matter how many cycles in PCR/initial quantity/numbers of copies made
- ratio will be the same
Explain how different types of enzymes are used to produce a gene package (4)
- restriction endonucleases/enzymes used to cut out the desired gene
- the same endonuclease/enzyme in used to oped the plasmids
- producing complementary/correspoinding sticky ends
- ligase is used to join/splice/attatch/adhere/anneal gene into plasmid
explain the advantage of farmers having herbicide resistance plants (3)
- will not kill crop but will kill other plants/weeds
- reducing competition in the field
- allowing increased yield
explain why environmentalists might have legitimate objectiosn to using GM crops resistant to herbicide resistance gene (2)
- increased use of herbicide
- reduction in biodiversity / lead to herbicide resistante weeks/superweeds / bioaccumulation in the food chain
- dispersal of pollen from crops engineered for herbicide resistance to wild relatives/weeds may lead to herbicide resistant weeds/superweeds
- dispersal of pollen from crops engineered for herbicide resitnace to other crops
- may contaminate organic crops
- GM crops produces a new protein
- unknown effects of eating a new protein
explain the named enzymes would be used to cut genes from algae and splice them into cameline plants (3)
- restriction (endonuclease) enzyme used to cut out gene/DNA
- sticky ends
- same restriction enzyme used to open DNA in plasid
- ligase used to insert/anneal/splice gene into vector/plasmid
explain why feeding genetically modified camelina seed which produce more omega 3 - fatty acids for farmed fish could benefit biodiversity (1)
- less wild fish will be harvested to feed farmed fish
descrive three ways in which a DNa molecules differs from an RNA molecule (2)
- double stranded (not single/RNA is single stranded)
- deoxyribose not riboe
- thymine not uracil
- larger molecule
State what is meant by a restriction endonuclease (2)
- it cuts DNA
- at a specific base sequence
Suggest how the CRISPR technique could be used to modify mosquito eggs to produce sterile adult mosquitoes (3)
- make guide RNA with complementary sequence of target gene/fertility gene
- instert CRISPR/ cas 9 into eggs/cells
- and incubate/allow to grow/mature
- remove the gene that makes them fertile/affects meiosis
explain how releasing these sterelised mosquitoes into the wild might beenfit humankind and suggest an ethical reason for not doing so (3)
- reference to reduced fertility in mosquitoes
- less mosquitoes = less malaria
- reference to right of humans to make another species extinct/effect on removal from food chain/exosystems/biodiversity/unknown effect of GM mosquitoes in the environment
describe how a cDNA fragement containing bt gene can be prepared (3)
- extract mRNA from the bacterium (which is synthesising the proteins)
- use reverse transcriptase to synthesis single strand of DNA/cDNA using the mRNA as a template
- use DNA polymerase to produce double stranded DNA
- sticky ends are added to the end of each DNA strand of the DNA
- the DNa is copied many times using PCR