Year 12s: what will be the first way you research your future options? >>

This discussion is now closed.

Check out other Related discussions

AQA BIOL2~3rd June 2013~AS Biology (Now Closed)

Scroll to see replies

Reply 760

looloo4

Does anyone know if we have to know about the chloride shift? (haemoglobin)

Reply 761

Jimmy20002012

Original post by looloo4

Does anyone know if we have to know about the chloride shift? (haemoglobin)

What the hell is that?? :wink:

Posted from TSR Mobile

Reply 762

homefind

Original post by looloo4

Does anyone know if we have to know about the chloride shift? (haemoglobin)

No just shift caused by CO2

Posted from TSR Mobile

Reply 763

Secret.

Original post by looloo4

Does anyone know if we have to know about the chloride shift? (haemoglobin)

Original post by homefind

No just shift caused by CO2

Posted from TSR Mobile

The chloride shift doesn't shift the curve like CO2 does, it's a counteract to the negative ions in the plasma caused by CO2 release, but no I don't think we need it for the exam.

Reply 764

Jimmy20002012

What kind of a 6 marker could we get with insect gas exchange? :smile:

Posted from TSR Mobile

Reply 765

Jay95

hey my teachers didnt explain the entire antibiotics unit!

we missed it out completel so can someone explain that unit to me please?

thanks!

Reply 766

LiamDaly

Original post by LiamDaly

Also why, I mean WHY is there only cohesion in the apoplastic pathway and only osmosis in the symplastic pathway? PLEASE

Posted from TSR Mobilehh

The one thing I can't get my head around - why they exclusively only use cohesion or water potential.

Posted from TSR Mobilehh

Reply 767

LiamDaly

Original post by LiamDaly

Also why, I mean WHY is there only cohesion in the apoplastic pathway and only osmosis in the symplastic pathway? PLEASE

Posted from TSR Mobilehh

The one thing I can't get my head around - why they exclusively only use cohesion or water potential.

Posted from TSR Mobilehh

Reply 768

krishio

Hey guys does anyone know how to work out 5)d)ii) in june 2010? You're a genius if you can...

Reply 769

x-Sophie-x

Original post by krishio

Hey guys does anyone know how to work out 5)d)ii) in june 2010? You're a genius if you can...

2^3.

Because there are 3 pairs of chromosomes.

Posted from TSR Mobile

Reply 770

x-Sophie-x

Original post by Jimmy20002012

What kind of a 6 marker could we get with insect gas exchange? :smile:

Posted from TSR Mobile

I'd hazard a guess at them asking the features in relation to gas exchange. I'd probably mention the spiracles etc, I hope that doesn't come up.

Posted from TSR Mobile

Reply 771

Jimmy20002012

Could anyone explain the counter current in fish, don't seem to get it??? :smile:

Posted from TSR Mobile

Reply 772

Tee Logan x

Original post by Jimmy20002012

Could anyone explain the counter current in fish, don't seem to get it??? :smile:

Posted from TSR Mobile

Water flows in one direction and blood flows in the other direction. This means that there is constantly a steep concentration gradient as oxygen rich blood in being taken away and blood without oxygen is being brought in so that oxygen can quickly diffuse into the blood. I think :tongue:

Reply 773

Simran Mars Foster

Original post by x-Sophie-x

I'd hazard a guess at them asking the features in relation to gas exchange. I'd probably mention the spiracles etc, I hope that doesn't come up.

Posted from TSR Mobile

I don't think so because there wouldn't be enough to write about? 3 marker maybe.

Reply 774

Simran Mars Foster

I'm confused between species and biodiversity. My book doesn't explain it well.

Reply 775

x-Sophie-x

Does anyone have a list of the definitions we might be asked for this paper? :smile:

Reply 776

x-Sophie-x

Original post by Simran Mars Foster

I'm confused between species and biodiversity. My book doesn't explain it well.

Hmm, I'm not great at this topic either but I'll try my best.
There are 3 types of biodiversity; genetic, ecological (habitat) and species.

Species diversity is basically referring to how many different species there are in a community AND how many of each different species there are in that same community.

Hmm, what else...

Reply 777

marseille_h

Hi , how many chromosomes do we get at the end of meiosis if we start with 46?

Thanks :smile:

Reply 778

Magenta96

Original post by marseille_h

Hi , how many chromosomes do we get at the end of meiosis if we start with 46?

Thanks :smile:

I think it's 23 because meiosis produces haploid gamete cells which have half the amount of usual chromosomes and so half of 46 is 23. It also explains that's why when two gametes each fuse together, they form a zygote with the full 46 set of chromosomes. :smile:

Reply 779

Liam2404

I find unit 2 much easier than unit 1 for some reason, its just the massive hsw that end up pulling my marks down - like that 15 marker on asthma and the 8 marker on the parometer in the jan 2013 paper! Hope because there was quite alot of hsw in the unit 1 paper theres less in this one! :smile: