AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

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Original post by ??????????????????

My teacher said active transport. Because the water needs to be in the leaf so there is a high concentration. Might differ between boards.
Don't think sucrose transport in plants are in AQA not sure cos I hate phloem and xylems.

Do you mean ions move in by active transport? I'm pretty sure water moves in by osmosis.
Meh hate OCR, should have done AQA.

Reply 361

liviaaa

Original post by hash007

I'm doing OCR, it moves up due to active transport?? Isn't it osmosis, water lost from leaf so due to cohesion tension theory another water molecule is pulled up? All water molecules stick (cohesion) to each other, and they stick to the walls of the vessels (adhesion) to form long continuous chains of water in the xylem.

And what about Sucrose?

It moves from roothair cell, to xylem by osmosis. Up the xylem by cohesion-tension, cappilarity or root pressure. NOT active transport - that requires ATP, and the xylem is made from dead cells.

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Anyway this is AQA unit 1, not OCR unit 2. :tongue:

Reply 362

??????????????????

Original post by hash007

Do you mean ions move in by active transport? I'm pretty sure water moves in by osmosis.
Meh hate OCR, should have done AQA.

I'm not that good at transpiration but I think there is a higher concentration of water in the leaves. That's where the water is going so why would it be low concentration since it has to end up there.

Reply 363

emmaaa65

describe how cholera is transmitted and how it causes disease. use your knowledge of water potential in your answer (5 marks)

Reply 364

liviaaa

Original post by EffKayy

Define disease?!? omg panic panic, i don't know how to define it? When a pathogen invades and causes harm?

Add ethanol, shake it, water? Cloudy-white?

Disease - a condition with a specfic cause, it can be a physical/mental disorder, when the body functions in a non-normal or less effiecent manner. Can include symptoms.

Yup :smile:

Reply 365

Twilight =D

i think i'll just learn elastic tissue which controls air flow

will this be correct ?

Reply 366

??????????????????

Original post by liviaaa

Yeah listen to this person. I can do from roots to stem but nothing above it. Hate xylem and phloem. Dunno what they even are? Organs?

Reply 367

EffKayy

Original post by hash007

do you mean ions move in by active transport? I'm pretty sure water moves in by osmosis.
Meh hate ocr, should have done aqa.

this is unit 1. Please do not confuse us and leaveeeeeeeeeeee.

Reply 368

EffKayy

Original post by liviaaa

Disease - a condition with a specfic cause, it can be a physical/mental disorder, when the body functions in a non-normal or less effiecent manner. Can include symptoms.

Yup :smile:

Oh okay!
Do you think they can ask us to give the mechanism of breathing? inspiration and expiration, for 5marks?

Reply 369

liviaaa

Original post by emmaaa65

describe how cholera is transmitted and how it causes disease. use your knowledge of water potential in your answer (5 marks)

Cholera is transmitted through polluted drinking water. Causes carrier proteins to be permenatly open so chloride ions escape into lumen, lowering water potential, water moves down water potential by osmosis, causing diahrea.

Reply 370

liviaaa

Original post by EffKayy

Oh okay!
Do you think they can ask us to give the mechanism of breathing? inspiration and expiration, for 5marks?

Yup possibly. :smile:

Reply 371

Ramin Gorji

Original post by liviaaa

Some random Q:

-Define disease

-What's the biochemical test for a lipid?

- What is the role of the nucleus?

Disease is any malfunction of the body which results in poorer health

2cm^3 of sample is added to a test tube same with ethanol to dissolve the sample add water and shake if its cloudylipid is present.

Role of the nucleus is to act as the control centre of the cell through the production of mrna and hence protein synthesis
Retain the genetic information of the cell in the form of DnA and Chromsoomes
Manufactures ribosonal rna and ribosomes

Reply 372

??????????????????

Original post by emmaaa65

describe how cholera is transmitted and how it causes disease. use your knowledge of water potential in your answer (5 marks)

Fave topic but Unit 2?

Chlorea is transmitted in dirty water. Can survive for a few days in the air. Generally a week. It causes the Cl- channel proteins to open so the Cl ions enter the lumen which lower the water potential causing water to enter the the lumen which gives water faeces and diarrheoa and flatulance. Treated with ORS which consists of Na+ glucose and water so that the Na+ and glucose enter the body cells lowering water potential there so water leaves the lumen and enters the body cell.

Reply 373

liviaaa

Original post by Ramin Gorji

Yeah I think that's all right. :smile:

Reply 374

liviaaa

Original post by ??????????????????

Chloera is unit 1?

Reply 375

??????????????????

Original post by liviaaa

Chloera is unit 1?

I'm not sure now.
Yup CGP says 1.3 :frown:

Reply 376

TlanTlan

Original post by emmaaa65

describe how cholera is transmitted and how it causes disease. use your knowledge of water potential in your answer (5 marks)

Cholera is a prokaryotic bacteria which causes severe diarrhea in infected individuals. It is spread by poor sanitation and poor sewage systems, and poor hygiene such as not washing hands with anti-bacterial soap. It's method of action is that is binds to carbohydrate receptors on the epithelial cells of the small intestine due to the shape being complementary to receptors on the cholera bacterium surface. This causes chloride protein channels to open and chloride ions flows out into the lumen of the intestine by diffusion. This causes a decrease in the water potential of the lumen to a level lower than that in the epithelial cells and blood, so water flows out of the blood, across the epithelial cells into the lumen of the intestine by osmosis. This causes severe and extreme diarrhea which can result in serious dehydration which can result in death if untreated by oral rehydration therapy.

Reply 377

emmaaa65

Original post by ??????????????????

yeahh
i wrote

Cholera is transmitted through water that is contaminated with the bacterium. This can be spread by preparing/eating food with hands that have faecal contamination with the bacterium. The cholera bacterium produces a toxin that binds to chloride ion protein carriers on the epithelial cells of the small intestine. This changes the shape of the protein carrier and chloride ions are released into the lumen of the small intestine. This lowers the water potential of the small intestine causing water to travel by osmosis from epithelial cells, blood and surrounding tissue which have a relatively high water potential compared to that of the lumen. This loss of water from the blood and tissue causes dehydration in the individual and diarrhoea.

i always forget to write about ORS and all that stuff