OCR AS Biology (F211) - Jan 2013.

Reply 1980

How did it go guys??? Hard or easy? Btw there was a question about cell division and about yeast cells seperating, I forgot what the question said, but it spoke about multicellular organisms! What did everyone write...

This was posted from The Student Room's iPhone/iPad App

Reply 1981

SRJ

Some aspects of the paper were straight forward others were not..
The 5 marker after budding screwed me over i wrote about cytokinesis in animal and plants could this be right? Does anyone remember how exactly the question was phrased?

Also the last question?? About the surface areas

Also what was missing it the table?

Reply 1982

xKaylax

2

Original post by SuperMushroom

For how cell signalling happens,
Did people put has glycolipids which have complementary pairs that can bind to them to trigger a cell response? :smile:

Isn't it the gyloproteins that have a complementary shape to molecules? And the glycoproteins/glycolipids act as anitgens to identify the cell as self/non-self? The main role of the glycolipids is adhesion between cells to form tissues I thought :/

Reply 1983

Incisive

9

The relief when I finished was unexplainable.
Was a fairly decent paper, now to revise chemistry!

Reply 1984

Zain369

Original post by lfmox

Everyone here put 3 lol!

We went to our biology teacher after and tried to get as much info as we could from our heads to her before it faded away. I was buzzed at the time and can't remember much but I think she said 3 was right, but then she said she'd look at the paper tomorrow anyway. Nothing to worry about really, I won't be too upset if I get that one wrong honestly, but it will be really annoying if I do.

Teacher might not be right anyway - that's only from what I can remember and I wasn't taking in very much info at the time

When your teachers looked at it, tell me please? dont have biology till friday now -_-

Reply 1985

student$

Original post by Zain369

But im sure it said ignore the scar?

I thought it already gave the SA of the car as 0.5?

I did 4 x pi x 1.5 to find SA of yeast then / by 0.5 and got 56

Reply 1986

lfmox

9

Oh god haha there was this girl in our exam who WOULD NOT stop coughing!!!

It was so bloody irritating argh.

Sorry had to write that down.

Reply 1987

burnatte4

Original post by SRJ

Some aspects of the paper were straight forward others were not..
The 5 marker after budding screwed me over i wrote about cytokinesis in animal and plants could this be right? Does anyone remember how exactly the question was phrased?

Also the last question?? About the surface areas

Also what was missing it the table?[/QUOTE]

For this question, I wrote that the units were missing and then gave an example of the type of measurement to use.

The question about budding threw me too, because i had only generally revised for and focused more on bohr shift, heart etc. but i wrote about it seperating from the parent cell
- anything i could remeber basically, but i defo think you will get marks for that :smile:

Reply 1988

mljones

Did anybody else make the mistake of talking about photosynthesis in the photometer question and therefore the movement of the bubble rather than transpiration? I guess it does have an effect as water is required so is there a chance this could be correct?

Reply 1989

JamesNeedHelp2

5

I dont remember there being a 5 marker on budding. I thought that the 5 marker was telling us that yeasts cells have different type of cell division than large multicellular organisms so i assumed that they were talking about how mitosis/meiosis takes place in large multicellular organisms?

Reply 1990

Zain369

i put glycoproteins for the cell receptor not glycolipids :s

Reply 1991

gashaan055

i'm mixed up, which exam are you guys doing. i hv done biology igcse o level today

Reply 1992

lfmox

9

Original post by Zain369

When your teachers looked at it, tell me please? dont have biology till friday now -_-

I don't think I have biology until Friday either - I have tomorrow off for studying for my Psychology exam which is at 2pm tomorrow! So I'll have no time to see her until Friday me thinks.

Reply 1993

xKaylax

2

What did people put as the missing items from the table in the photometer question??
I put the time they were studied for and the units of measurement (i.e. cm/mm etc) :/

Reply 1994

rainingdewdrops

Original post by Mule

Well I think it went reasonably well for me. Here's the stuff I did if anyone's interested about the controversial topics being discussed:

I put yeast as budding because i'm pretty sure budding is how they reproduce asexually. Mitosis is a part of this budding.

I got 36 for the yeast cells.

Ribosomes as the smallest organelle

I put test tube 3 but i'm pretty sure this is wrong as I didn't read the question properly. When it's homogenised, there can still be 2 organelles within the same tube I assumed it had to be one organelle for each tube but I'm pretty sure this is wrong, as lysosomes and mitochondria have relatively the same size, (I think it was centrifuged, can't remember) then the lysosomes would be in the same test tube as the mitochondria which is why it broke down bacteria.

For the organisation of cells one, I don't remember it talking about how cell division is involved? I talked about it anyway about how cells divide and differentiate into them at specific areas.

I'm a little worried about the potometer question what did the student miss out of the table and how could the results be improved?

im not sure but i put they forgot to write the units for the mean rate of the air bubble.

Reply 1995

biochemphypsy

Did any one put mitochondria for the test tube that did nothing and lysosomes for the on that made digestive enzymes?

Reply 1996

JamesNeedHelp2

5

Original post by Zain369

i put glycoproteins for the cell receptor not glycolipids :s

For this question i think you could have put glycoproteins or glycolipids or both i just wrote "Glycoprotein/glycolipids".

Reply 1997

rozi16

Original post by HarryW95

Did the paper not end on the question;
Which organelle from part (i) is smallest in size? Please don't tell me I missed the last section..

No that wasn't the last question. There were few more questions after that, I think you missed those out :/

Reply 1998

burnatte4

Original post by JamesNeedHelp2

I dont remember there being a 5 marker on budding. I thought that the 5 marker was telling us that yeasts cells have different type of cell division than large multicellular organisms so i assumed that they were talking about how mitosis/meiosis takes place in large multicellular organisms?