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

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I'm feeling a bit better about this now- I've been using the technique for answering that I saw in one of the reports, and I feel like I don't start to panic-write answers :P Might be a different story at 11am tomorrow though.

Good luck to everyone sitting it tomorrow :smile:

Yeah you have to read the questions carefully to see what they actually want you to write. I hate how specific you have to be on some of the questions though.. :/ but goodluck.

Reply 1141

Majeue

Original post by mastermdc

Hi, this is not mentioned in my book but the mark scheme says it. Just wondering if any of you can confirm whether it is true. It says that when memory cells detect their specific antigen/pathogen then they differentiate into plasma cells, which release the antibodies that neutralise the foreign pathogen.

I didn't realise that memory cells can turn into plasma cells. What else can they do?

Yeah, when memory cells notice the same foreign antigen again, they divide into plasma cells which then release antibodies.

Reply 1142

rival_

Original post by Adil96m

How would you describe the global impact of HIV/T.B/Malaria??

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Data interpretation question sir. You'll never need to know the extent or spread of diseases at A Level.

Reply 1143

rival_

Original post by scott18044

I'm feeling a bit better about this now- I' :redface:

ve been using the technique for answering that I saw in one of the reports, and I feel like I don't start to panic-write answers :P Might be a different story at 11am tomorrow though.

Good luck to everyone sitting it tomorrow :smile:

Wait isn't it 9?

Reply 1144

Hello...

Anybody up for some Revision??

What are the short term effects of damage from tar (From smoking)

Reply 1145

scott18044

Original post by rival_

Wait isn't it 9?

Yeah, I meant when I get out of there just before 11. :smile:

Reply 1146

kited4

and im in the front row -.-
ohhh the joys

Reply 1147

Sam_1996

Good luck to everyone!

Reply 1148

samiwami

Original post by Hello...

Anybody up for some Revision??

What are the short term effects of damage from tar (From smoking)

WOOHOO YAY

Tar - Paralysis of cilia and enlargement of goblet cells causes mucus to build up and smokers cough occurs - chronic bronchitis

You're question issss....
What are the roles of the T and B lymphocytes?

Reply 1149

ssflcb

Hi guys I just did the specimen paper and as it does not give grade boundaries , any idea what grade 75/100 would be ? Any suggestion would be appreciated. Thank you :smile:

Reply 1150

Hello...

Original post by samiwami

Yes!! also tar mat cause an allergic reaction causing the smooth muscle to contract making the lumen smaller and restricting the airflow...
T-Killer cells and T-Helper cells are selected during clonal selection after exposure to antigen (from pathogen)
T-Killer cells search for infected cells and bind to them to secrete Hydrogen Peroxide to kill pathogen
T-Helper cells release interleukins to activate the B-Cells
B-Cells undergo clonal expansion, some differentiate to form plasma cells which release antibodies,
The other B-Cells differentiate to form B-Memory cells which remain in the body to provide an immunological memory
Describe the structure of an antibody

(edited 10 years ago)

Reply 1151

Elle_95

A, it's usually 72 or 73 for an A I think and specimens tend to be harder

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Reply 1152

ssflcb

Original post by Elle_95

A, it's usually 72 or 73 for an A I think and specimens tend to be harder

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Thank you. that paper was really hard like some of answers were nothing like the mark scheme :/

Reply 1153

samiwami

Original post by Hello...

Yepp that's correct :smile:

Antibodies have a hinge region that is flexible so it can bind to many antigens
A constant region that allows it to attach to phagocytes
A variable region that binds to complementary shaped antigens (to undergo neutralisation)
I think I'm missing a point...

What are coenzymes, and their function?

Reply 1154

Loiks94

Link to the specimen paper please?

Reply 1155

Elle_95

Specimens are usually nasty, if the past papers have been going okay then it should be fine! And you still got an A even if it was weird.. Can someone please explain variation to me? I get the basic genetic and environment but what's all the continuous discrete etc? There was like a 7 marker in a past paper earlier..

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Reply 1156

ssflcb

Original post by Loiks94

Link to the specimen paper please?

http://www.ocr.org.uk/Images/67660-unit-f212-molecules-biodiversity-food-and-health-specimen.pdf

Reply 1157

ssflcb

Original post by Elle_95

Continuous variation is when species vary withen a range and there are no distinct categories. Such as the height and weight in humans.This type of variation is affected by genes and the environment most of the time.

Discontinuous varitation is qualitative and there are no intermediates but two distant categories such as the sex and eye colour of humans. This type of variation is mostly only affected by genes.

I hope that kinda helps ? :smile:

Reply 1158

Elle_95

Brilliant, thanks :smile:

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Reply 1159

senS

Whats biological catalyst again? It was a 2 marker, I need ms answer