OCR Biology F212 Revision [3rd June 2013] (Now Closed)

OP

Original post by Ché.

Yes, yes!
I am up for it...
:biggrin:

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Define the term antigen (2)

Reply 561

Original post by BioGeek

Define the term antigen (2)

Antigen:
"A toxin or other foreign substance on the surface of the cell that activates an immune response in the body producing antibodies."

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Reply 562

Danny786

10

For antigens can't you just say ''molecules that stimulate an an immune response''

Reply 563

niceguy95

14

Can some explain species evenness

As in the ey things we need to know

Reply 564

OP

Any1 up for revision? :biggrin:

Original post by Danny786

For antigens can't you just say ''molecules that stimulate an an immune response''

Nope,

A good answer is, a protein molecule which in on the surface of a pathogen which stimulates an immune response.

Original post by Ché.

Antigen:
"A toxin or other foreign substance on the surface of the cell that activates an immune response in the body producing antibodies."

2/2

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Reply 565

the A* guy

2

Original post by BioGeek

Any1 up for revision? :biggrin:

i am

Reply 566

Original post by Danny786

For antigens can't you just say ''molecules that stimulate an an immune response''

That absolutely correct!
However... For the full two marks, you might need to include more of the topic-specific vocabulary - surface, the production of antibodies as that's its function really.
I have a thing where I write in full sentences almost all the time; since my discovery the QWC marks, I always have!
Marks count!
LOL. :smile:

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(edited 10 years ago)

Reply 567

OP

Ask me a question please

Reply 568

Original post by BioGeek

Any1 up for revision? :biggrin:

Nope,

A good answer is, a protein molecule which in on the surface of a pathogen which stimulates an immune response.

I have one for you guys...
Get your long answer heads on!

"One of the symptoms of smoking is the development of a smokers cough.
Explain how smoking causes a smoker's cough AND how the cough itself can lead to further problems with the lungs over a long period of time. (7)."

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Reply 569

Original post by BioGeek

Ask me a question please

"Describe the role of memory cells when the Influenza virus enters the body."
(3).

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Original post by BioGeek

Ask me a question please

Explain how smoking can lead to thrombosis or a Stroke. (6 marks)

Reply 572

OP

Original post by Ché.

"Describe the role of memory cells when the Influenza virus enters the body."
(3).

.

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Memory cells circulate in the blood.
Memory cells provide immunological memory to a particular antigen.
Memory cells can differentiate into plasma cells to secrete antibodies

Original post by the A* guy

Explain how smoking can lead to thrombosis or a Stroke. (6 marks)

Smoking contains nicotine.
Nicotine causes platelets to become sticky.
If the membrane that covers the plaque is damaged
Red blood cells begin to stick to the exposed fatty deposits
A blood clot then forms and is known as thrombus.
This constricts the lumen of the artery.
This reduces the oxygen uptake in the blood.
Less oxygen is received at the brain.
Which causes a stroke.

Reply 573

OP

Original post by the A* guy

Explain how smoking can lead to thrombosis or a Stroke. (6 marks)

Can you post the model answer to that question please?
Thanks :biggrin:

Reply 574

Dejir

How much do I need for A if i got C in unit 1 abd 39/40 for practical

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Reply 575

OP