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OCR AS Biology (F211) - Jan 2013.

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Just done a paper where it was 42/60 for an A... If only they were the grade boundaries in this exam xDDD
(June 2009) Although the paper did have some tricky concepts, but if you revised them its quite hard to get them wrong.

Reply 321

joe1545

Original post by rgeorg3

does anyone know where i can get jan2013 predicted mock paper please ???????

I dont think any ones done any, not like they have with chemistry.

Original post by Harriet : )

Any predictions as to what could come up? :smile:

My teachers put a few topics together she thinks will be in the paper these are:

Factors affecting the rate of transpiration - has never been examined
Electron micrographs of cells and organelles
Describing the fluid mosaic molecule- never been questioned
Hamoglobin both 02/CO2
Tidal volumes, expiratory reserve that stuff
Comparison of plant and animal cell mitosis
Sources and sinks

These are my teachers predictions of what may come up, dont hold me responsible for i know they may ask everything that was on the June 2012 paper, highly unlikely, and if they do im ****ed :biggrin:

Edit: Also, many of the questions some students or TSR users have been asking above are very good questions, that may come up in the paper.

(edited 11 years ago)

Reply 322

lilyobz

Original post by LolaGonzalez

high five there =/ any good revision tips? I'm seriously worried about those two points in the syllabus XS

i could scan up my short and snappy revision guide if u want? great for last minute revision, it skips the uneccesary and goes straight to the point

Reply 323

BioGeek

comparsion of plant and animal cell mitosis????? what????????

Reply 324

theworld

Describe the cardiac cycle, with reference to the action of the valves in the heart.

Suppose this was a 6 mark, how would you get 6/6?

Reply 325

imthe12

Original post by lilyobz

i could scan up my short and snappy revision guide if u want? great for last minute revision, it skips the uneccesary and goes straight to the point

Can u make a small revsion guide on the topics/questions which could possible could come up as stated above? E.g factors which affect transpiration

Reply 326

theworld

Original post by lilyobz

i could scan up my short and snappy revision guide if u want? great for last minute revision, it skips the uneccesary and goes straight to the point

yes please :smile:

Reply 327

scienceboy16

Do you guys reckon this papers going to be the toughest yet since its the last january exam?

(edited 11 years ago)

Reply 328

LolaGonzalez

Original post by lilyobz

i could scan up my short and snappy revision guide if u want? great for last minute revision, it skips the uneccesary and goes straight to the point

yes please could you? I'm really struggling with those two topics =/

Reply 329

morvenrkr

Hey im taking this exam in 9 days :eek:

I only started the course in november! I think revisions going ok done some past paper but not been getting any more that 35 ish :frown:

does anyone have any revision tips?

ps i have links to past papers and some notes :smile:

Reply 330

ErHi?

Original post by theworld

Describe the cardiac cycle, with reference to the action of the valves in the heart.

Suppose this was a 6 mark, how would you get 6/6?

Mention Diastole - heart filling with blood

Atrial systole - filling with blood so pressure rises above ventricle as atrial contracts pushing blood into ventricle and forcing the atrio ventricular valves open.

Ventricular systole - as the contraction on the ventricles begins, the pressure will rise above the pressure in the atria and the blood will be forced back, snapping the valves shut preventing back flow.

As the blood is pumped into the artery the pressure in the artery will reach higher than the pressure in the ventricle, the semi lunar valves will be forced shut preventing back flow into the ventricles.

I assume that would get you 6 marks?

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Reply 331

theworld

Original post by ErHi?

you mean close? The AV valves open in diastole and close in atrial systole. This is to prevent backflow of blood into the atrium.

Reply 332

JamesNeedHelp2

Anyone who wants to revise?

Reply 333

JamesNeedHelp2

Original post by theworld

you mean close? The AV valves open in diastole and close in atrial systole. This is to prevent backflow of blood into the atrium.

Describe the cardiac cycle, with reference to the action of the valves in the heart.

* In Diastole, blood flows into the ventricles from the atria through the open atrioventrical valves.

* In atrial systole, the atria contract pushing any remaining blood in the atria into the ventricles. Blood fills the atria ventricular valve pockets causing them to snap shut. This is to prevent black flow.

* In ventricular systole, all the 4 valves are closed. The ventricels begin to contract, meaning that the pressure in the major artries is higher than the pressure in the ventricles so the semilunar valves are closed.

* However, when the pressure in the ventricles exceeds the pressure in the major ateries, the semilunar valves are forced open pushing blood out of the major ateries.

(edited 11 years ago)

Reply 334

Delz101

I need someone to explain term homologous pair of chromosomes! The book really doesn't explain it well :frown:

Reply 335

JamesNeedHelp2

Original post by Delz101

I need someone to explain term homologous pair of chromosomes! The book really doesn't explain it well :frown:

Homologous pairs of chromosomes are approximately the same length and thier centromere is at the same position. One is from the father and the other is from the mother. While their genes are in the same order, they have different alleles that code for different things. For example one of the chromosomes might code for brown hair, while the other might code for blond hair.

(edited 11 years ago)

Reply 336

the A* guy

Original post by Delz101

I need someone to explain term homologous pair of chromosomes! The book really doesn't explain it well :frown:

A homologous pair of chromosomes is a pair of chromosomes that contain the same genes, but different alleles of the same genes. One of the chromosomes is maternal and the other is paternal. During Meiosis only one of the chromosomes from each homologous pair goes into a daughter cell, creating 4 daughter cells, which are haploid.

I would not worry about homologous pairs of chromosomes, as they came up in june 2012, so its very unlikely for it to come up in jan 2013. :biggrin:

Reply 337

the A* guy

Original post by BioGeek

comparsion of plant and animal cell mitosis????? what????????

Questions comparing plant and animal cell's mitosis are normally about the differences,

For example: In plants the cell WALL forms at the cell's equator.
In animals no cell wall, only membrane

No centrioles in plant mitosis

in plants mitosis only occurs in meristem cells
in animals all cells expect gametes perform mitosis

etc

Hope this helps! :biggrin:

Reply 338

the A* guy

Original post by joe1545

I dont think any ones done any, not like they have with chemistry.

My teachers put a few topics together she thinks will be in the paper these are:

Factors affecting the rate of transpiration - has never been examined
Electron micrographs of cells and organelles
Describing the fluid mosaic molecule- never been questioned
Hamoglobin both 02/CO2
Tidal volumes, expiratory reserve that stuff
Comparison of plant and animal cell mitosis
Sources and sinks

These are my teachers predictions of what may come up, dont hold me responsible for i know they may ask everything that was on the June 2012 paper, highly unlikely, and if they do im ****ed :biggrin:

Edit: Also, many of the questions some students or TSR users have been asking above are very good questions, that may come up in the paper.