Relevant study design dot points• techniques that apply DNA knowledge (specifically gene cloning, genetic screening and DNA profiling) including social and ethical implications and issues
• the distinction between genetically modified and transgenic organisms, their use in agriculture to increase crop productivity and to provide resistance to insect predation and/or disease, and the biological, social and ethical implications that are raised by their use
• strategies that deal with the emergence of new diseases in a globally connected world, including the distinction between epidemics and pandemics, the use of scientific knowledge to identify the pathogen, and the types of treatments
• the concept of rational drug design in terms of the complementary nature (shape and charge) of small molecules that are designed to bind tightly to target biomolecules (limited to enzymes) resulting in the enzyme’s inhibition and giving rise to a consequential therapeutic benefit, illustrated by the Australian development of the antiviral drug Relenza as a neuraminidase inhibitor
• the use of chemical agents against pathogens including the distinction between antibiotics and antiviral drugs with reference to their mode of action and biological effectiveness.
What is the difference between gene therapy and gene transfer?
[quote author=millie96 link=topic=151609.msg777025#msg777025 date=1412553211
Is gene transfer the same as gene therapy?
[/quote]
Gene therapy is an application of gene transfer
What do we need to know about rational drug design
How much do we need to know in terms of rational drug design?
Probably just how a drug can be produced with a SPECIFIC COMPLEMENTARY shape to a substance or part of the substance (pathogen/enzyme) to inactivate its function
And that they're designed to target a specific enzyme so as to kill a microorganism/cure a disease. The whole point of rational drug design is that you find a particular enzyme target and then knock it out by inhibition.
Inhibition.
The fact that the structure of a particular enzyme's active site needs to be identified. A potential inhibitor, complementary to the active site of the enzyme is created. This is then exposed to the enzyme via injection or other means of delivery system. This 'inhibits' the enzyme's functionality as substrate is blocked out, meaning the artificial drug is successful and efficient.
How do gene probes work?
How do gene probes allow you to find a particular gene?
I know that they are "labelled", that is with a fluorescent dye or a radioactive label, but when it is inserted, does the target gene become visible because of the label (gene probe)?
Thank you
Yes because DNA is a clear substance. However, the probe will only fluoresce under UV light.
What’s the difference between recombinant DNA and a transgene?
What's the difference between 'recombinant DNA' and a 'transgene'?
Well the difference between the two is that, transgene is a gene that is not native/belonging to an organism (a gene that is transferred from one organism to another) whereas recombinant DNA is DNA that has essentially been combined with other, different DNAs (manipulated DNA - contains more the one organisms' DNA).
An easy way of remembering it is that DNA is double-stranded right? So during recombination, the strands are unzipped into two, thus allowing another strand to bind with either of the original strands (aka. a transgene) resulting in recombinant DNA.
Pro’s and con’s and ethical concerns of artificial selection and gene therapy
Can someone list the pro's and con's (and ethical concerns) of artificial selection/domestication/selective breeding and also gene therapy?
Artifical selection/Selective Breeding:
Pros;
1.) Aesthetic appeal
2.) Economic value (higher crop yields, shorter harvest time etc)
Cons;
1.) Lack of genetic diversity which could lead to the loss of disease-resistant alleles, hence increasing the susceptibility of the organisms to disease.
2.) Continuation of traits which are disadvantageous for survival/reproduction
e.g. English bulldogs have been selectively bred to maintain a 'pure line' but their shortened muzzles and flattened faces cause respiratory problems. So many features artificially selected for can be detrimental to the survival of the organism.
Genetic modification:
Pros;
1.) Can permanently alter the genotype to produce "ideal" phenotypes.
2.) Can reduce the use of toxic insecticides in crops.
e.g. In Bt corn the corn has been genetically modified to produce insecticidal proteins protecting it from many of its pests and this reduces the use of toxic insecticides.
Cons;
1.) Unwanted gene flow between GMO's and non genetically modified organisms: unwanted spread of GMO's.
Hope that helped. Sorry don't know much regarding ethical issues.
What’s the difference between gene therapy and gene transfer?
Is gene transfer the same as gene therapy?
Gene therapy is an application of gene transfer
How much do we need to know about rational drug design?
How much do we need to know in terms of rational drug design?
Probably just how a drug can be produced with a SPECIFIC COMPLEMENTARY shape to a substance or part of the substance (pathogen/enzyme) to inactivate its function
And that they're designed to target a specific enzyme so as to kill a microorganism/cure a disease. The whole point of rational drug design is that you find a particular enzyme target and then knock it out by inhibition.
Inhibition.
The fact that the structure of a particular enzyme's active site needs to be identified. A potential inhibitor, complementary to the active site of the enzyme is created. This is then exposed to the enzyme via injection or other means of delivery system. This 'inhibits' the enzyme's functionality as substrate is blocked out, meaning the artificial drug is successful and efficient.
What’s the difference between transformed and transfected?
What is the difference between "Transformed" and "transfected" ?
It's supposed to be that transformation involves bacteria and transfection involves eukaryotic cells, though in reality nobody adheres to this distinction. Both are normally used interchangeably.
What’s the difference between artificial selection and natural selection?
Can someone list a few differences and similarities of artificial selection and natural selection?
Artifical selection is when humans intervene and selectively breed desired individuals
Natural selection is the natural process of "survival of the fittest" where natural selective pressures result in fit individuals thriving
What’s the difference between genetic testing and genetic screening?
Hey, can someone please clarify the difference between genetic testing and genetic screening.
Thanks in advance!!
Test: I want to test you for this disease because I think you might have it
Screen: I'm gonna test a whole bunch of people and hopefully find someone with the disease
Social and ethical implications of DNA profiling and gene cloning
Hey everyone
What's the difference between social and ethical implications?
And what kind of social and ethical implications exist in gene cloning and DNA profiling?
Thanks in advance!
Social: Effects people. eg. Not all farmers will be able to afford a GM crop
Ethical: Just bad (at least to some people). eg. Humans shouldn't be allowed to interfere with nature - 'playing god'
For DNA profiling
Social:
-If you find out that you have a genetic disorder that means our parent does too.(eg Huntingtons - something you don't find out until later in life)
-Not everyone will be able to afford DNA profiling
-May be charged more for life insurance
-May lose/not get job due to possible inability to work in future
Ethical:
-Should you be allowed to find out if there's no treatment
-When used in embryo selection it alters our gene pool.
There's plenty of others but that's just what I came up with. I'm sure there's some that fit into both as well.
The differences between "social" and "ethical issues can be hard to determine, as they overlap a lot, but here's a brief distinction:
- ethics is about right or wrong actions, for example: breeding and planting GMOs, or claiming genes as intellectual property.
- social issues tend to be more specific towards the effect of an action on people, and society in general, for example: the effects of selling GMOs to the public, stuff like that.
- you can talk about them as if they are a single unit tho, nothing wrong with that.
Here are some social and ethical implications of DNA profiling (+ pros, - cons)
+ regular health monitoring of individuals can be implemented, and preventative action can be taken on individuals with genetic disorders/diseases.
+ couples can plan their pregnancy, and make preparations based on the results of DNA profiling/screening for their child
+ a negative result on screening/profiling in relation to genetic diseases can often reduce emotional stress
- a positive result of a genetic disease may induce stress, and can be an emotional burden
- DNA profiling and genetic screening can hinder with one's privacy
- DNA profiling and genetic screening can often be inconclusive, and data can be difficult to interpret
Social and ethical implications of genetic cloning (and also genetic engineering technology which produces GMOs)
+ producing enhanced crops, and organisms, which translates to technological advancement
+ higher quality of life
+ alleviate poverty (higher yielding crops)
+ reduce the detrimental effects of diseases (check out golden rice, transgenic rice with beta carotene which turns into vitamin A, to aid with vitamin A deficiencies within poorer nations)
- genetically modified organisms or cloned genes may affect ecosystems as gene flow might occur between natural and modified organisms (some genes may result in a selective advantage, which affects the allele frequencies of populations)
- companies might claim segments of genes as intellectual property (unethical), and charge high prices for any research/development involving the specific gene.
- GMOs can affect the production of traditional food, and might or might not be adequate substitutes for these traditional food items in providing the required nutrition.
- thorough, rigorous and independent testing of GMOs are required to ensure that the segments of cloned genes do not affect the quantity of production, and gene flow between modified and natural populations that can lead to devastating consequences.
How are GMO’s used in agriculture?
How are GMOs and transgenic organisms used in agriculture to increase crop productivity and to provide resistance to insect predation and/or disease?
GMOs and trangenic organisms (transgene is a type of genetic modification) are organisms which contain genetic material from other sources (usually organisms of other species, which makes a GMO a transgenic organism). For plants, this could mean that one can modify a specific section of a gene within the plant to increase its crop yield, which in turn increases their crop productivity in agriculture. Sections of genes which codes for resistance towards pests, weeds and microbes can also be inserted within the genome of an organism (these genes may be expressed and a protein or toxin could be produced to fend off these pests, weeds and microbes).
LifeisaConstantStruggle beat me to it whilst i was typing but i will add this,
There are two main ways that insect predation is stopped. They are given a gene that makes them resistant to insecticide/herbicide, they can then be sprayed a lot, killing the pests but not the plant. Or they produce a protein (eg. Bollard cotton) so that, when an insect eats the plant, the protein will kill them.
Also worth noting that genetic technology can be used to identify a crop's genotype - deciding which should be used in the next generation, which is more accurate than relying on phenotypic characteristics (ie. normal selective breeding). This is used a lot, especially with cattle for milk production but these organism have not been altered so they are not GMO's.
How much detail do we need to know about social/ethical issues surrounding gene technology?
how much detail do we need to know about the ethical and social issues surrounding gene tech?
For the exam you need to be able to list and very briefly describe a few positives and negatives of gene tech in terms of how it benefits society and also be able to describe a few social and ethical issues that might arise from its use. You won’t need to memorise entire lists or anything like that.
For your SAC it might be a bit different though. It really depends on your teacher, for mine I had to know about one issue in depth. If your teacher doesn’t tell you in advance to learn about a specific issue/give you handouts on it then the above should be enough.
I doubt it will be assessed in detail on the exam, you’ll probably get a question in relation to a specific scenario.
How do bacteria become resistant against antibiotics?
How does bacteria become resistant against antibiotics when people overuse or misuse them?
In your question, we can apply Darwin's theory of evolution and natural selection. So in the population of bacteria, there will already be variation in the population. Therefore, there may exist certain bacteria which are somehow different and are resistant to the antibiotics (due to a random mutation). Then when a person uses antibiotics, it acts as a selective pressure. All of the bacteria without the resistance will die while a small amount of bacteria resistant ones will remain (they have a selective advantage). So when you overuse the antibiotics, you will kill all of the non-resistant ones leaving the resistant ones to breed with each other and they will increase in numbers slowly and then eventually when you try to cure the same infection with the antibiotics, most of the bacteria will be resistant
As well as natural selection, antibiotic resistance can be spread between bacteria. Genes for antibiotic resistance are commonly found on plasmids. Plasmids can be transferred between bacterial species, effectively giving more and more bacteria the resistant gene.
What do we need to know about emerging diseases?
What should we know about emerging diseases for the exam?
3.
Spoiler
• strategies that deal with the emergence of new diseases in a globally connected world, including the distinction
between epidemics and pandemics, the use of scientific knowledge to identify the pathogen, and the types of
treatments
My interpretation of this is that you don't need to actually know about emerging diseases as such, you just need to know about how to identify pathogens and treatment options.
What should we know about types of treatments for pathogens for the exams?
What should we know about types of treatments for pathogens for the exams?
4. Just need to know about antibiotics/antivirals/etc. including what type of pathogen they can be used against.
Which DNA profiling techniques do we need to know?
Hi,
So I'm a little confused with DNA profiling - some of the resources I have mention STR's only, whereas others mention VNTR's, and others mention RFLP's... are they all the same process or are they different? And do we need to know all for the exam?
VNTRs and STRs are actually the same thing it's just an arbitrary distinction between the length and quantity of those repeats (STRs being shorter and less repeats).
RFLPs are restriction fragment length polymorphisms so depends on certain restriction enzymes and where they cut.
Make sure to check the study design if you are unsure if anything is required/not required.
What do we need to know about transgenic crops?
Hi guys, what exactly do we need to know about transgenic crops in this SD dot point?
- The distinction between genetically modified and transgenic organisms, their use in agriculture to increase crop productivity and to provide resistance to insect predation and/or disease, and the biological, social and ethical implications that are raised by their use
Do we need to know how they are made or any examples? Thanks
For that dot point you don’t need to know how they’re made, but I think there’s a different one that refers to it? You do need to know a bit about how they’re made in order to distinguish between transgenic and gmo though.
You don’t need to know an example for the exam however you might have to for your SAC (I did).
You need to know:
-definitions and differences between transgenic and GMO’s
- their use in agriculture (making crops bigger, making insect that eat them die, making them resistant to insecticide/pesticides so that more can be sprayed on them)
-biological issues - things like wiping out natural plants
-social issues - e.g. farmers who can’t afford the modified plants going bankrupt
-ethical issues - e.g. ‘playing god’
Why do we use STR’s for DNA profiling?
Why do we use STR regions for DNA profiling?
They're highly variable regions, so the chances of peoples being the same are low - hence they can be used to create a unique DNA profile (sort of like why we use fingerprints)
Why does not finishing a course of antibiotics contribute to antibiotic resistance?
Can someone please explain to me why not finishing a course of antibiotics contributes to antibiotic resistance?
Bacteria can be partially resistant to antibiotics, meaning that the antibiotics aren't quite as effective as they would normally be. So if you only use half the course, you only half kill the bacteria, and then the partially resistant bacteria grow back and then constitute the bacteria that get passed around, then they can evolve to become fully resistant.
What’s the difference between gram-negative and gram-positive bacteria?
Hi!
Can somebody please explain the difference between gram negative and gram positive bacteria? Do we need to know this for the study design?
Thanks
Gram staining is to classify whether bacteria have peptidoglycan present in their cell wall or not. Gram positive means that they do have peptidoglycan present, and gram negative means that it is not present. This is useful to know, as bacteria with a certain cell wall composition can be more susceptible to certain antibiotics. And yes, I believe this falls under " the use of scientific knowledge to identify the pathogen" on the study design
Can rationally designed drugs be treated as foreign by the immune system?
I've got a few more questions.
1) Can rationally designed drugs be detected as foreign and treated as antigens by the immune system?
1. I'd imagine not. I mean, it's possible but they're very small molecules and they're not cells/don't produce proteins like bacteria/viruses. (Definitely not for VCE)
Can antisense mRNA be a type of rationally designed drug?
2) For the context of VCE biology, can antisense mRNA being used as a silencer be used as a form of 'rationally designed drug' or does that fall under a different category?
2. For VCE, no. A rationally designed drug is one made specifically to fit into a molecular shape, for VCE you just need to know about enzyme inhibitors.
study design
the concept of rational drug design in terms of the complementary nature (shape and charge) of small molecules
that are designed to bind tightly to target biomolecules (limited to enzymes) resulting in the enzyme’s inhibition
and giving rise to a consequential therapeutic benefit, illustrated by the Australian development of the antiviral
drug Relenza as a neuraminidase inhibitor
What is ELISA and why is it used?
3) What is ELISA and why is it used?
Not 100% sure on the other ones, so I will leave them for someone else, but for ELISA...
ELISA (Enzyme-Linked Immunosorbent Assay) is a technique that uses an antibody-enzyme complex. The antibody section of the complex binds with the pathogen antigen. The enzyme ‘s usual substrate is then added and reacts with the enzyme, producing a colour change that can be detected.
The process is as follows:
1. Antibodies for the suspected antigen (of the pathogen) are added to the bottom of a well
2. The blocking agent is added to fill any areas not bound by the antibody.
3. Swabs from a patient’s sample are added. If the antigen is present in the sample, it attaches to the antibody. If the antigen is not present in the sample, it does not attach to the antibody.
4. An antibody with an enzyme attached is added. If the antigen has attached to the antibody, this second antibody attaches to the other end of the antigen. If the antigen has not attached, this second antibody does not attach either.
5. The plate is treated is that the solutions in the wells turn a particular colour only in the presence of the antigen-antibody complex.
Note: between each of the above steps, a washing step occurs to remove any loose particles.
The strength of the colour indicates the quantity of antigens present. The darker the colour, the more antigens are present, and therefore the more infectious the person is.
(Sorry... just copied it directly from my notes so hopefully it makes some sense )