GCSE OCR 21st Century Triple Science (CBP1-7) Thread

Okay people. What would be your points for a 6-marker on DNA technology for genetic testing? I need help with putting them into concise points while still clear and understandable...

Bbc bitesize explains it quite well, i just summarised what they said and got it down to about one side of A4
I think the main thing would be to make sure you use all the key words: isolation, replicate, centrifuge, gene probe, use of UV light

These would be my answers for a B7 6 marker on genetic modification/testing

Genetic modification:

The desirable gene that makes the required protein is isolated from the DNA
The gene is then replicated and many copies are made of that gene
A vector (e.g plasmid, virus) is a carrier used to insert the new gene into cells
Successfully modified individual cells are chosen, as not all cells will be successfully modified


Genetic testing:

A blood sample is taken (e.g from the arm) for testing
DNA is isolated from the white blood cells
A gene probe is made by a strand of complimentary bases labelled with a fluorescent marker
The gene probe is mixed in DNA to find the faulty gene, if it's present then the gene probe (complimentary bases) will lock together
A UV light is shined on the gene probe to find the faulty gene, if it's there then it'll glow and tell you where it's located

Can someone explain the genetic probe DNA test thing in note form as simply as possible? D:

Centrifuge?

Hmm..does anyone know WHY the sample has to be isolated from the white blood samples? My CGP book is quite confusing because it says ''it's quick and easy to take a blood sample, that contains lots of white bloog cells'' but don't we want to take out the white blood cells? Ah..confused.

Hmm..does anyone know WHY the sample has to be isolated from the white blood samples? My CGP book is quite confusing because it says ''it's quick and easy to take a blood sample, that contains lots of white bloog cells'' but don't we want to take out the white blood cells? Ah..confused.

The white blood cells are removed when the blood is removed. They use them because they contain a nucleus with DNA (unlike red blood cells). What is it specifically that is confusing you?

Damn you posting a minute before me.

"Describe how microorganisms are used in industry, give examples and explain them"
what are the points we would make for this question? I dont know if im misinterpreting it

Off topic once again, but in the C456 the first question was about two similarities with the reaction of alkali metals and water... I put that they produced an alkaline solution and hydrogen gas, that's fine right? My minds just had one of them moments where it's brought a question back into my head and I'm doubting.

Sorry I worded that question horribly, I meant to say "Describe WHY microorganisms are used in industry, give examples of how they are used and explain why they are used for that".
So basically:

1.) They reproduce rapidly under the right conditions so products can be made quickly. They have plasmids - these can be genetically modified so you can make the microorganism produce the product you need. Their biochemistry is quite simple - fewer reactions happen in microorganisms than in humans, this means you can make the microorganism produce things that they normally wouldn't without causing them major problems. They can make complex molecules that are difficult to produce artificially. There aren't any ethical concerns with using microorganisms - you could grow loads of them and throw them in a bin without upsetting anyone.
2.) They are used for antibiotics by growing penicillium mould in a fermenter. Also A single-celled protein made by fungi used to make meat substitutes for vegetarian meals. (Quorn).
Also for enzymes for making food, like cheese can be made by a microorganism that is genetically modified to create chymosin (important enzyme in rennet) to produce a vegetarian substitute for cheese. ('Cause rennet usually comes from the lining of a calf's stomach).
Enzymes for washing powders, enzymes produced by bacteria can be used in washing powders because they break down stains like amylase enzymes remove carbs stains (e.g. jam).
Biofuels - microorganisms can be used to make fuel, like yeast can be used to produce ethanol by the waste produce of anaerobic respiration which can be used for car fuel known as 'gasohol'. And microorganisms can be used to produce biogas which is used for heating, cooking and lighting. Its made by the fermentation of plant and animal waste containing carbs.

Wow thankyou so much! That is extremely helpful! Thankyou thankyou thankyou

The gene probes are used in genetic testing to find a faulty allele. This is the process:

You take a blood sample from the person, from their arm is the most common method.
Your blood contains white blood cells and DNA, so you want to separate your DNA from the white blood cells.
Then, you want to create a gene probe. Gene probes are a strand of complimentary bases (A, T, C, G) that sticks to the faulty gene. You add a fluorescent marker to it too.
Then, you mix the gene probe with DNA so the complimentary bases stick to your DNA (AT, CG) and if there's a base that doesn't match, you'll find the faulty gene.
To make sure that you've found the faulty gene, you shine a UV light onto the gene probe that the fluorescent marker finds, if it glows then you'll find the faulty gene and know where it's located.