The Student Room Group

F215 - Revision thread 13th June 2011

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Original post by fortunecookie
Would you guys want to do a revision thread quiz type thing where you write a question and then someone below answers it, writing a new question underneath?


Yeah sounds good!
Can't promise i'll be answering many though.. haven't even finished my notes yet and am probably on track for an E :tongue:
Original post by fortunecookie
Would you guys want to do a revision thread quiz type thing where you write a question and then someone below answers it, writing a new question underneath?


:yep: .. It would be useful to throw in some synoptic questions too :tongue:



Right then, who's going to be brave enough to post the first question? :ninja:
Is this right for sequencing of the genome?

Genomes are mapped to find out which part of the Genome they come from. Information that is already known is used such as the location of microsatellites.

Samples of the Genome are mechanically broken down into sections of around 100,000 base pairs long.

These sections are then placed onto Bacterial Artificial Chromosomes (BAC’s) and then transferred to E.coli.

As the cells grow these sections are copied many times, and this is referred to as a clone library.

To sequence the BAC’s, cells containing the BAC are taken and cultured. DNA is extracted from the cells and cut into smaller fragments. Different restriction enzymes are used on a number of sections to give different fragment types.

The sample of DNA is then placed into a reaction mixture with primers, free nucleotides and taq polymerase. However, also in the reaction mixture are nucleotides referred to as ‘terminator nucleotides’ and they are fluorescent in colour. They bind to DNA in the same way as free nucleotides but they stop the fragment from replicating any further. Each of the four nucleotides A, T, G, and C is a different fluorescent colour.

As the template is copied many times, each time terminator nucleotides bind at random in different positions, and stop it replicating any further. This means that each fragment is a different length. The shortest is one nucleotide in length, the second shortest two nucleotides in length and so on up to the longest fragment which will be the one being sequenced. All the fragments are known as a set of Nested fragments.

The fragments are then placed in an electrophoresis tank. The shorter the fragments the faster it will travel through the gell. As the fragments reach the end of the gel, a laser reads the colour of the end nucleotide (terminator nucleotide).

Is then shown as a graph showing direct readings of the results.

:s
Reply 563
Original post by Kidms001
:yep: .. It would be useful to throw in some synoptic questions too :tongue:



Right then, who's going to be brave enough to post the first question? :ninja:


Discuss the advantages and disadvantages of artificially cloning plants? (4)

:d
Ok ill go first. Explain how nucleur transfer can be used in therapeutic cloning (non-reproductive cloning)?
Reply 565
Original post by slacker07906
Is this right for sequencing of the genome?

Genomes are mapped to find out which part of the Genome they come from. Information that is already known is used such as the location of microsatellites.

Samples of the Genome are mechanically broken down into sections of around 100,000 base pairs long.

These sections are then placed onto Bacterial Artificial Chromosomes (BAC’s) and then transferred to E.coli.

As the cells grow these sections are copied many times, and this is referred to as a clone library.

To sequence the BAC’s, cells containing the BAC are taken and cultured. DNA is extracted from the cells and cut into smaller fragments. Different restriction enzymes are used on a number of sections to give different fragment types.

The sample of DNA is then placed into a reaction mixture with primers, free nucleotides and taq polymerase. However, also in the reaction mixture are nucleotides referred to as ‘terminator nucleotides’ and they are fluorescent in colour. They bind to DNA in the same way as free nucleotides but they stop the fragment from replicating any further. Each of the four nucleotides A, T, G, and C is a different fluorescent colour.

As the template is copied many times, each time terminator nucleotides bind at random in different positions, and stop it replicating any further. This means that each fragment is a different length. The shortest is one nucleotide in length, the second shortest two nucleotides in length and so on up to the longest fragment which will be the one being sequenced. All the fragments are known as a set of Nested fragments.

The fragments are then placed in an electrophoresis tank. The shorter the fragments the faster it will travel through the gell. As the fragments reach the end of the gel, a laser reads the colour of the end nucleotide (terminator nucleotide).

Is then shown as a graph showing direct readings of the results.

:s


Yeah, that's right
I just made a quiz on this site, you have to sign up to view it but it's free and so worth it!
I'm going to make more for the other sections :smile:
http://getrevising.co.uk/account/quizzes/ocr_biology_unit_5_section_1_protein_synthesis_and_cellular_control_a2
Original post by Waqar Y
Discuss the advantages and disadvantages of artificially cloning plants? (4)

:d


Advantages

1. Can produce many genetically identical plants from one original plant with all the desirable characteristics present
2. Can be grown any where in the world and similarly transported around the world.
3. Callus can be genetically modified
4. Disease free as grown in aseptic conditions
5. Cn be harvested at same time which is less time consuming and saves money.

Disadvantages

1. Genetic uniformity can make them susceptible to a newly mutated pathogen, hence a lot of plants may die.]
2. Expensive as is labour intensive, requires aseptic conditions and specialist equipment
3. Requires training. :tongue:
Original post by titchygirl1701
I just made a quiz on this site, you have to sign up to view it but it's free and so worth it!
I'm going to make more for the other sections :smile:
http://getrevising.co.uk/account/quizzes/ocr_biology_unit_5_section_1_protein_synthesis_and_cellular_control_a2


Good :smile: I got really bad. 79%. I got promotor ad operator region mixed up :s
Reply 569
Similarities between LEARNED and INNATE behaviours? (3 marks)
Original post by slacker07906
Ok ill go first. Explain how nucleur transfer can be used in therapeutic cloning (non-reproductive cloning)?


I'm guessing that nuclear transfer will produce a mass of undifferentiated stem cells which are genetically identical (in their allele sequence) to the donor of the nucleus in the original cell.

These stem cells can then become any type of cell or tissue required (based on conditions or whether there are initiator/regulatory hormones present) to treat an injury or other condition without grafting or any harm to animals which would normally be used for this purpose. :dontknow:

EDIT: This tissue will not have the issue of rejection by the immune sequence (since the DAN is the same), so immunosupressor drugs won't be required.
(edited 12 years ago)
Original post by Rup
Similarities between LEARNED and INNATE behaviours? (3 marks)


Haha is there any similarities? Could it be they both allow the mammal to take action which enable them to survive, theyare both affected by environmen i.e. the alleles in innate behaviour that have been selected for are due to the environment that have resulted them to evolve by natural selection and learned is modified by exerience from surrounding.

Answer?

Also, explain the types of innate behaviour and its advantages?
Reply 572
Hey everyone, just a quick question.
My teacher hasn't gone through the Galapagos spread, is it essential?
I've self taught most of this stuff but I really wanna focus on revision now and not waste time doing the above spread!
Original post by Kidms001
I'm guessing that nuclear transfer will produce a mass of undifferentiated stem cells which are genetically identical (in their allele sequence) to the donor of the nucleus in the original cell.

These stem cells can then become any type of cell or tissue required (based on conditions or whether there are initiator/regulatory hormones present) to treat an injury or other condition without grafting or any harm to animals which would normally be used for this purpose. :dontknow:


Yep. Its simply that a cell from a human suffering from a degenarative disease can be fused with an unucleated egg cell from a cow or other appropriate mammals. The resulting 'hybrid' cells Can be grown onto provide replacement tissues for these people. Furthermore, it is preferred to testing drugs on these tissues rather than actual patients. Also, in principle, a somatic cell fro a person suffering with a degeranative disease can be fused with another human cell. Then they are grown on to tissue or organs in labs. These can then be implanted into the person suffering from the disease.
(edited 12 years ago)
Original post by MattyC93
Hey everyone, just a quick question.
My teacher hasn't gone through the Galapagos spread, is it essential?
I've self taught most of this stuff but I really wanna focus on revision now and not waste time doing the above spread!


The title of the spread states that the Galapagos islands are an example where humans have had an affect on the animal and plant populations.

It explains how the increase in population has placed an extra demand on resources that are struggling to be met. An oil spill damaged the coastal areas, and clearing land for agriculture/food has almost made one species of tree and shrub extinct in that area. Fishing has placed fish/sharks and sea cucumbers under threat, and the exploitation of the tortoises for food has placed them on the endangered list. The last remaining tortoise is now in captive breeding. The book then states that this has had an adverse effect on the sea ecology, including disruption of food chains.

It then explains the adverse affects of introducing outside species to the environment. How goats outcompete local organisms for grass/shrubs and how they trample the remaining resource, as well as eating a unique species to the islands nearly to extinction. Disease has been bought in and one tree has out-competed another tree.

Next is the conservation of the area. It explains how new species are quarantined and any arriving vessel is thoroughly searched. Natural pest control measures have been put in place (ladybirds introduced to eat insects that destroy plants) and how goats have been culled to try and protect local wildlife.

It finally explains how any new conservation need to take into account local population's life, including sustainable management. This includes no-go areas for tourists and the setting up of wildlife reserves.

:rolleyes:
Original post by slacker07906
Yep. Its simply that a cell from a human suffering from a degenarative disease can be fused with an unucleated egg cell from a cow or other appropriate mammals. The resulting 'hybrid' cells Can be grown onto provide replacement tissues for these people. Furthermore, it is preferred to testing drugs on these tissues rather than actual patients. Also, in principle, a somatic cell fro a person suffering with a degeranative disease can be fused with another human cell. Then they are grown on to tissue or organs in labs. These can then be implanted into the person suffering from the disease.


That is a very good point actually.

Thanks :biggrin:
Reply 576
Original post by titchygirl1701
I just made a quiz on this site, you have to sign up to view it but it's free and so worth it!
I'm going to make more for the other sections :smile:
http://getrevising.co.uk/account/quizzes/ocr_biology_unit_5_section_1_protein_synthesis_and_cellular_control_a2


Great quiz :smile: however, too much apoptosis leads to cell loss and degeneration not the formation of tumours.
In the quiz it marked me wrong for the correct answer.
Original post by MoMatrix
Great quiz :smile: however, too much apoptosis leads to cell loss and degeneration not the formation of tumours.
In the quiz it marked me wrong for the correct answer.


Ah man! Sorry! My bad, read it the wrong way round in the book :colondollar: thanks for pointing it out, I'll change it now :smile:
Original post by titchygirl1701
Ah man! Sorry! My bad, read it the wrong way round in the book :colondollar: thanks for pointing it out, I'll change it now :smile:


I was gonna say that as well :biggrin:
Original post by sportycricketer
I was gonna say that as well :biggrin:


What would I do without you lot :tongue:

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