A2 Biology OCR June 2015 Revision Thread

Original post by Xx-FireDragon-xX

Predictions for this exam:
Methods and advantages of conservation
Process of muscle contraction
Translation/Transcription of proteins
Last but not least: SUSTAINABLE TIMBER

Good luck everyone! You can thank me later :wink:

Sincerely, Xx-FirEdrAgonSnipe-z-Xx

are you talking about f215?

Reply 2182

Original post by Maham88

are you talking about f215?

F215?!?!? What?!?!?

Reply 2183

Original post by Xx-FireDragon-xX

Predictions for this exam:
Methods and advantages of conservation
Process of muscle contraction
Translation/Transcription of proteins
Last but not least: SUSTAINABLE TIMBER

Good luck everyone! You can thank me later :wink:

Sincerely, Xx-FirEdrAgonSnipe-z-Xx

That isn't today's exam, today is F214 x

Reply 2184

Original post by Nadiabafekr

That isn't today's exam, today is F214 x

babe i think i know what paper im doing x

Reply 2185

domcandrews

Original post by Xx-FireDragon-xX

F215?!?!? What?!?!?

Looooooooooool

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Reply 2186

Original post by domcandrews

Looooooooooool

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stfu dom what u on about looool

Reply 2187

EspDe97

Original post by Shehla123

Can someone help me on pregnancy test!! Are there monoclonal antibodies at one end which hcg binds to and then this conplex binds to immobilising antibodies at other end attatched to bead so theres a presence of the line?!?? HHELP

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Posted this earlier on in the thread, hope it helps! :smile:

During pregnancy the placenta produces the hormone human chorionic gonadotrophin (hCG). Some of it is lost to the urine and only pregnant women produce hCG, so a urine sample is used to test for pregnancy as hCG will only be present if the woman is pregnant. When a woman takes a pregnancy test, urine passes into the reaction zone of the test stick and some of the monoclonal antibodies there bind to hCG, others do not. These monoclonal antibodies recognise one specific feature of hCG and will only bind to that one; they have blue beads attached to them. All of the monoclonal antibodies pass down to the testing zone which contains polyclonal antibodies which are immobilised. These polyclonal antibodies can bind to numerous parts of hCG so are able to bind despite the fact that the monoclonal ones are attached. Since the polyclonal antibodies are immobilised on the strip, the hCG and thus the blue beads are fixed in this zone, causing it to turn blue. The monoclonal antibodies that didn't bind to hCG move along the strip to the control zone which also contains immobilised antibodies. The monoclonal antibodies bind to the control antibodies, which turns this zone blue as well since all the monoclonal antibodies have blue beads attached. Two blue lines indicates pregnancy.

Reply 2188

Original post by Shehla123

Can someone help me on pregnancy test!! Are there monoclonal antibodies at one end which hcg binds to and then this conplex binds to immobilising antibodies at other end attatched to bead so theres a presence of the line?!?? HHELP

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The HCG acts as an antigen and binds to monoclonal antibiodies with a blue bead on them however the blue line is only activated once they join to the immobilised antibiodies, the whole antibody complex then moves the the immobilised antibodies and binds again therefore showing a blue line and then the control line forms when the monoclonal antibodies without HCG binded to them bind to the control antibodies

(edited 8 years ago)

Reply 2189

mybutton jammed

everyone ****ing YOLO it

Reply 2190

domcandrews

Original post by Xx-FireDragon-xX

stfu dom what u on about looool

Lol

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Reply 2191

Original post by Xx-FireDragon-xX

babe i think i know what paper im doing x

Today is only unit 4 tho, translation and transcription is unit 5, which is on the 17th June....

Reply 2192

Original post by Nadiabafekr

Today is only unit 4 tho, translation and transcription is unit 5, which is on the 17th June....

aha but thats where you are wrong! Today is the 8th, the 17th is next week!

Reply 2193

Beanhead456

Good luck guys :smile:

Reply 2194

Original post by Xx-FireDragon-xX

aha but thats where you are wrong! Today is the 8th, the 17th is next week!

Good luck with your unit 5 exam today then :smile:

)

Reply 2195

Shehla123