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OCR Biology F215 Control, Genomes and Environment Fri 15 June 2012

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Original post by Fatima0065
is this to do with all the belt transect..quadrat stuff if so.i havent leanr it becasue it came up in the jan2012 ppaer..ask me another one pplease :smile:


no its not its about sweep netting , pitfall traps, using light trap any method will do and need to describe like how to sample and use pooter e.t.
sure :wink:

Describe the xenotransplantiation and name the enzyme in pigs (3)
Original post by otrivine
no its not its about sweep netting , pitfall traps, using light trap any method will do and need to describe like how to sample and use pooter e.t.
sure :wink:

Describe the xenotransplantiation and name the enzyme in pigs (3)


xenotransplation refers to trabnsplatation of cells tissures or organsm of differnt species.
the enzyme is enzyme1,3 tranferase.
Original post by Fatima0065
xenotransplation refers to trabnsplatation of cells tissures or organsm of differnt species.
the enzyme is enzyme1,3 tranferase.


excellent :wink:
Original post by otrivine
no its not its about sweep netting , pitfall traps, using light trap any method will do and need to describe like how to sample and use pooter e.t.
sure :wink:

Describe the xenotransplantiation and name the enzyme in pigs (3)


can you give me a sample answer fot that please(abou the insects) :smile:
last question: what is allotrasnplantation
Original post by Fatima0065
can you give me a sample answer fot that please(abou the insects) :smile:


ok the key words ill give you so you should use this is a unit 2 question but could ask as a synoptic question :smile: right
1) use sweep netting/pitfall traps/light trap
2) if using sweep netting you need a pooter to count the number of insects so it prevnets them from flying
3) to this experiment you need to radom sample before you start experiment like generating a pair of random numbers
4) when you count the number of insects present record it using a table then from there to plot a graph to be able to see the distribution of insects present in that particular habitat
Original post by Fatima0065
last question: what is allotrasnplantation


allotransplantion- is transplanting tissue/organs with the same species
would anyone be kind enough to tell me everything there is to know about ascisic acid? It's so confused in textbooks with everywhere say different things-

just done really get it's role in ageing + absicssion.. some say it increases it some day it decreases it

and something about it being affect by dry conditions/ drought?

HELP PLEAAAAASE :smile:
Original post by The_original_one
This module is so hard :/ Can someone explain to me in depth what germline therapy and somatic therapy is? I slightly get the somatic but not the germline. And also the DNA probing and stuff is really confusing I need a lot of help :/ Please try not to explain from the textbook because I don't get it reading it from their so as much in your own words please.


Somatic therapy
is when the gene you want is inserted into a vector like a liposome or a GMd virus. It targets mature body cells, so you inject the vector into the target area. This gene therapy can work in one of the 2 ways:
1) gene therapy by augmentation- inserting a dominant version of a gene into the the affected allele. This only works if the disorder is caused by a recessive allele e.g. Cystic fibrosis.
2) gene therapy by killing cells- the gene causes the cell to express a protein that would cause the cell to die e.g. In a cancer cell it would cause a foreign antigen to form so that it is recognised as foreign by the body's immune system and is killed off.

In somatic repeat treatments are required because the treated cells in our body naturally die and are again replaced by "ill" ones.

Germline therapy
Is when the genes of a ZYGOTE are modified in vitro so that as the zygote develops, it doesnt contain any "ill" genes and grows into a normal baby.

No repeat treatment is required and the modified "not ill" genes are passed on to the offspring of the zygote too.

Hope this makes sense :smile:
Original post by stressedoutbadly247
would anyone be kind enough to tell me everything there is to know about ascisic acid? It's so confused in textbooks with everywhere say different things-

just done really get it's role in ageing + absicssion.. some say it increases it some day it decreases it

and something about it being affect by dry conditions/ drought?

HELP PLEAAAAASE :smile:


ABA causes stomatal closure, so when there is a drought, the plant doesnt waste the water it has on transpiration. So during a drought ABA levels would be high
it also causes leaf, seed and fruit abscission (ageing), helps prolong seed dormancy, and slows down growth of many plant organs
Original post by Awkwardlife
ABA causes stomatal closure, so when there is a drought, the plant doesnt waste the water it has on transpiration. So during a drought ABA levels would be high
it also causes leaf, seed and fruit abscission (ageing), helps prolong seed dormancy, and slows down growth of many plant organs


thankyou :smile:
Reply 3911
According to my textbook, one of the structural genes in the lac operon of E. coli codes for the enzyme lactose permease which allows the cell to take up lactose.
But I was wondering, how did the lactose that bound to the repressor protein (and hence allow the enzyme to be synthesised in the first place) get into the cell?

Many thanks if anyone can help :smile:
Original post by SS*
According to my textbook, one of the structural genes in the lac operon of E. coli codes for the enzyme lactose permease which allows the cell to take up lactose.
But I was wondering, how did the lactose that bound to the repressor protein (and hence allow the enzyme to be synthesised in the first place) get into the cell?

Many thanks if anyone can help :smile:


Repressor protein has 2 binding sites, one complementary to the operator region another to lactose. When lactose binds it changes the shape of the repressor protein so it can't bind to the operator so the enzymes can be transcribed
Reply 3913
Original post by The Illuminati
Repressor protein has 2 binding sites, one complementary to the operator region another to lactose. When lactose binds it changes the shape of the repressor protein so it can't bind to the operator so the enzymes can be transcribed


Yes, but one of the enzymes that is transcribed allows lactose to be taken up by the cell. How could lactose have entered the cell in the first place if that enzyme had not yet been synthesised?

I can only assume that the enzyme (lactose permease) allows increased up take of lactose.

Anyhoo, it's not important but just a quirky point I wanted to highlight!
Original post by SS*
Yes, but one of the enzymes that is transcribed allows lactose to be taken up by the cell. How could lactose have entered the cell in the first place if that enzyme had not yet been synthesised?

I can only assume that the enzyme (lactose permease) allows increased up take of lactose.

Anyhoo, it's not important but just a quirky point I wanted to highlight!


Sorry, I misunderstood the question. That is right though.
Original post by Eviey
Hi I just wanted to ask could you please explain the difference between recombinant DNA and recombinant plasmid. I get really confused when to use which one. Thanks.


Recombinant DNA is a section of DNA (usually in the form of a plasmid) that has been formed by joining 2 sections of DNA from 2 different sources

A recombinant plasmid is the terms used to describe when the plasmid contains the donor DNA, and the sugar-phosphate backbone has been sealed by DNA ligase. A recombinant plasmid is a form of recombinant DNA.
Reply 3916
Sorry if this question has already been asked but I need help on homeobox genes!
The pages in the textbook are so wishy-washy, and while comparing the spec to the info in the book, it seems that they've given us wayy too much unneccessary info!
What do we exactly need to know for homeobox genes??
quick question, how many ways are ther in animlas of producling clones is it just: nuclear transfer and embroy splitiing
Original post by Shhh.
Sorry if this question has already been asked but I need help on homeobox genes!
The pages in the textbook are so wishy-washy, and while comparing the spec to the info in the book, it seems that they've given us wayy too much unneccessary info!
What do we exactly need to know for homeobox genes??


regulatory genes
affect the transcription of other genes
180 base pairs long
arranged in Hox clusters
important for the development of the body plan and segmentation
very important
One small change has large effect, those who are effected by the change won't be able to survive long enough to pass on their alleles
similar across kingdoms
Original post by Shhh.
Sorry if this question has already been asked but I need help on homeobox genes!
The pages in the textbook are so wishy-washy, and while comparing the spec to the info in the book, it seems that they've given us wayy too much unneccessary info!
What do we exactly need to know for homeobox genes??


Homeobax genes control the development of an organism, including polarity and positioning.
they code for protienn called homeodamins which acts as trasncription factors when they bind to a specific part of dna this inturn, causes expresion of certain allele by transcriptiona nd translation
homeobox gens are aranged in hox clusters.
if a pregnant women eats to much vitamin a(because witamin a is a morphogen-a substance that governs teh patterns of tissue develpoment) it may affetc the expression of the babies genes which ca cause cranial defromates etc...dnt know what els you should know :smile:

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