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Factors that cause the rate of osmosis to increase

Other than temperature and concentration, are there any other factors that would cause the rate of osmosis to increase?
light intensity and temp are linked - they increase the energy of the particles and also cause evapouration which means the solution or the potato will reqire more water - thus increasing osmosis. volume of solution - the greater the volume of water the less likely osmosis is to occur due to natrually occuring low to high concentraion movement of wate r- so the water will move into the potato and the other way round when the concentration of sugar or salt is high in the solution. The potato mass if higher means that there is more water in the potato decreasing the amount of osmosis from solution to potato and maybe increasing the osmosis from potato to solution. the shape effects the surface area - the greater the surface area the greater the chance of osmosis occuring increasing the rate. Time - the greater time the potato left for the more likely osmosis is to occur as it can happen ovcer longer periods of time that would not be noticed short term. Im at a level now and my knowledge of gcse coursework is a bit sketchy but i hope that helps.
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Statistics... =(

Im looking at the relationship between Leaf size and Light Intensity. Im going to be looking at leaf length and width.

I found that length and width of leaves are greater when light intensity is less (Leaves found in the shade).

So what kind of Statistical test should i use and why

1) Students T-Test
2) Mann Whitney U test
3) Spearman's Rank Correlation Coefficient

and what kind of graph should i do aswell? Scatter diagram or the Box and whisker diagram?

Will i have to do a different table and graph for both Length of leaf and Width of Leaf?

Plz help!! Thanks in advance!

You would have to use Spearman's Rank Correlation Coefficient because your finding out the relation between two variables; dependant and independant. You would use this statistical test to test the strength of the relationship.

I am not sure about the graph but i hope this helps :)  


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biology A2 coursework


The effect of the heavy metal barium on the growth rate of your plants.

for the above title i have to complete my P-skill for the coursework but i was unsure of what type of scientific information i should include. 
not many students seem to have carried out this investigation. if anyone has any information that could help me it would be really appreciated. 

Wow Erm Never seen this investigation before. For scientific research why don't you include other variables which may affect the growth rate of plants. Check on google or other coursework websites for a similar study carried out, or a study carried out with a different metal. You can gain free access in most of these websites by donating your past completed courseworks. Hope This Helps =)
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yeast respiration

Im trying to design an experiment which measures factors on respiration of yeast.

i need to know if bakers yeast performs aerobic respiration - and if so, would basic dough rise evenly if sealed in an air tight conatiner (pressed up against the glass).

would appreciate any help or even alternate experiment designs!
Hi,bluewombat.I have an alternative experiment whereby the rate of yeast respiration would be measured in terms of bubbles evolved over a specific period of time.So,lets make the above a little bit clearer.
In fact,factors affecting yeast respiration are temperature,pH,type and conc. of substrate,concentration of enzyme and inhibitor.

There is a simple experiment that you can carry out.just follow the steps:

Apparatus:1.Boiling tube,2.Thermometer,3.Test tubes,4.A gas delivery tube connected to the rubber bung. 5.stopwatch

Substance required:yeast,Glucose solution.

1.Place 5cm3 of yeast in a boiling tube.Then,add an equal amount of glucose solution.
2.Connect the bung to which a delivery  tube is attached to the mouth of the boiling tube.
3.fill about half a test tube with the end of the delivery tube in the water.
4.set a water bath at a specific the boiling tube in it.
5.Allow the tube like this for a few minutes to allow the yeast to adapt to its new environment.
6.After a few seconds bubbles would start to out of the delivery tube.
7.Start a stopwatch and count the number of bubbles evolved over 3 mins.
8.Hence,the rate of gas bubbles evolved can be calculated.

For more accuracy,the volume of carbon dioxide evolved can be measured.Variables such as temperature can  be varied by changing the temperature of water bath or the substrate conc. can  be varied using different conc. of glucose solution.

The above experiment can be used to investigate other variables.Of can improve it.
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Im stuck on ideas for my AS coursework

Any interesting ideas?
Effect of Catalase on Hydrogen Peroxide
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Mosaic model of membranes


Can anyone briefly describe the fluid mosaic model of membranes??

Any help is appreciated.



The fluid mosaic model of membrane is quite simple. It consists of phospholipid molecules lined up with different proteins interspersed within the molecules, hence the name mosaic. The reason its called fluid is because the molecules can rotate and are not really stationary, thus the 'fluid mosaic' model.

More ?
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Cell Biology


can anyone help me with a few things:


in a plant cell the -

a) storage of genetic information

b) protein synthesis granules

c) secretory materials

d) structure that controls the movement of materials into and out of the cell



why are lysosomes enclosed within membranes?

Any help will be much appreciated.

Lynsey x

a) Nucleus - The largest organelle in the cytoplasm of a eukaryotic cell is usually the nucleus, a structure that directs all the activities of the cell. The nucleus is like a manager who directs everyday business for a company and passes on information to new cells. The nucleus contains genetic blueprints for the operations of the cell.

b & c) Golgi Bodies - In cells, structures called Golgi Bodies are stacks of membrane-covered sacs that package and move proteins to the outside of the cell. Golgi bodies are the packaging and secreting organelles of the cell.

d)Cell Membrane - The cell membrane is a structure that forms the outer boundary of the cell and allows only certain materials to move into and out of the cell. Food, oxygen and water move into the cell through the membrane. Waste products also leave through the membrane.

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Biology help

Amber g.p
Does anyone know of any really good websites/tips (I don’t want actual answers to these!) to help me carry out for each of these coursework questions:

Should genetically modified food be banned?

Should gene therapy be used as a treat for all genetic diseases?

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Effect of bile concentration on digestion of fats by lipase

Bile emulsifies the fats, so it will cut them up into smaller globules. This increases the surface area of the fats, so the lipase can have a greater effect.

Therefore, as the concentration of bile increases, the rate of digestion will increase.

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Fish exchange


You'll be alot i you could help with this question

Explain how the direction o the flow of the blood and the flow of water increases the efficiency of the gill plate as an exchange?


Since water and blood flow in opposite directions a difference in concentration gradient is maintained as an equilbreum is never reached allowing more oxygen to be diffused through the gills.

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