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AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

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I've just finish revising like gone through all my notes I'm on a break at the moment, I'll do a couple of past papers before bed.

Yeah I'm going to have a break for Britains Got Talent, then past papers tomorrow. :smile:

Reply 81

AspiringGenius

Good luck! I'm doing B2 on Thursday!

Reply 82

liviaaa

Original post by AspiringGenius

Good luck! I'm doing B2 on Thursday!

Thanks

You mean a week on Thursday?

Reply 83

Sparkly-Star

I'm gonna go over all my notes again to check I know it all and a few past papers. :smile:

Reply 84

AspiringGenius

Original post by liviaaa

Thanks

You mean a week on Thursday?

My exam timetable says Thursday 19th. :s-smilie:

I can't understand why I messed up, it wasn't even hard! >_<

Reply 85

liviaaa

Original post by AspiringGenius

My exam timetable says Thursday 19th. :s-smilie:

I can't understand why I messed up, it wasn't even hard! >_<

Are you AQA? As the biology 2 is on the 26th?

Reply 86

TlanTlan

Yes AQA biology is 26th.

edit: For unit 2 that is.

Reply 87

AspiringGenius

Original post by liviaaa

Are you AQA? As the biology 2 is on the 26th?

I'll check that out at school. I suppose they're not putting it down a week late :smile:

Reply 88

EffKayy

Can we have a Q&A thing??

Reply 89

liviaaa

Original post by EffKayy

Can we have a Q&A thing??

Okayy..

How is the structure of the plasma membrane adapted to it's function?

Reply 90

Sparkly-Star

I am terrified of this exam! :cry2:

Reply 91

jones_wise

Original post by Sparkly-Star

I am terrified of this exam! :cry2:

Don't be! I'm sure you'll be alright! What did you get in the Jan exam?

Reply 92

emmaaa65

I need to get an A in this exam..... :frown:

soo not going to happen im soo worried! ive done so much revision but i always do badly in exams

Reply 93

LiviD

this is a good thread!!!
i expect a lot of stuff on immunity and heart aswell, although there was quite a bit of heart on the june 2010 so....
i just hate the 'how science works' questions! and the way the questions are worded is absolutely mental!! will let you know how i get on afterwards and we can compare our answers! :tongue:

good luck everyone!!!!!

Reply 94

Reminisce

Original post by liviaaa

Okayy..

How is the structure of the plasma membrane adapted to it's function?

Wow that's pretty broad, erm...

The plasma membrane is made up of phospholipids with a phosphate group which is hydrophilic and a fatty acid chain which is hydrophobic. Therefore, a bilayer with the phosphate group facing outwards and the fatty acid interacting with each other could maintain two environments with different conditions. The phospholipids will also allow only lipid soluble substances such as hormones and small substances such as carbon dioxide and oxygen to diffuse freely across the membrane (selectively permeable to be able to set up a concentration gradient with certain substances). The phospholipids are also flexible (fluid) so can move relative to each other and form vesicles for phagocytosis or exocytosis. It also allows proteins fit in the membrane to form channel/carrier proteins for the facilitated diffusion/active transport of ions or larger water-soluble substances across the membrane (intrinsic) or extrinsic proteins for cell recognition and for cells to adhere together.

How does asthma affect the rate of diffusion of oxygen?

Reply 95

eliteDNA

Original post by Reminisce

Wow that's pretty broad, erm...

How does asthma affect the rate of diffusion of oxygen?

When suffering an asthma attack, airways become enflamed because of the localised allergic reaction. This causes muscles in the wall bhronchiole to contract, and therefore narrowing of the airway. Also mast cells produce mucus which furhter narrows the airway. this means hat less oxgen can enter the alveoli, meaning the conc. gradient of O2 is lowered. This means slower rate of diffusion.

Correct me if im wrong anywhere.

Exaplain how glucose is abosobed during digestion?

Reply 96

eliteDNA

okay il answer my own question then...

-Firslty gluscoe is absorbed through into the epithelial cells by facilitated diffusion down a conc. gradient.
-Then Na ions are ACTIVELY pumped out of epithelial cells into lumen
-Meaning that conc. of Na is higher in lumen
-Glucose then diffuses passivley into epithelial cells via the Na glucose co-transporter.
-Conc. of glusoce high in the epithelial cell, so it diffuses into bloodstream.

Reply 97

clevercloggss

Original post by eliteDNA

Exaplain how glucose is abosobed during digestion?

Glucose moves into the epithelial cell, with sodium ions...viacarrier proteins. The sodium is removed from the epithelial cell into the blood via active transport regarding the sodium potassium pump. Theglucose then moves into the blood via fascilliated diffusion! :biggrin:

hehe :P xxx

Reply 98

eliteDNA

someone ask another question?

Reply 99

Insanity514

Could someone explain to me how to work out the serial dilutions question from the Jan 11 paper?

The student made up all the sodium chloride solutions using a 1.0 mol dm-3 sodium
chloride solution and distilled water.
Complete the table to show how he made 20 cm3 of a 0.2 mol dm-3 sodium chloride
solution.

Volume of 1.0 moldm-3 sodium chloride solution:
Volume of distilled water:

I don't know how to do it???