Yeah its 2d.(Original post by EffKayy)
advantages of tem
*small objects can be seen, also internal details
*higher resolution
*small wavelength of electrons
disadvantage
*staining process has to occur, and yet it is still black and white
*2d??
*artefacts may occur from prep.
*has to be in a vacuum
*living specimens cant be tested
*specimen has to be extremely thin
SEM ADVANTAGE - specimen doesnt have to be thin.
Also SEMs can have colour or is 3d. I forgot which one.
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AQA BIOL1 Biology Unit 1 Exam - 16th May 2011 watch
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View Poll Results: Are you resitting this unit?Voters: 193. You may not vote on this poll
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canthardlywait
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- 15-05-2011 15:43
Anyone know best way to achieve full marks, when asked to:
-Describe graph
-Explain graph
and also whats the best way to answer an "Evaluate" question.
Any help is much appreciated. -
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- 15-05-2011 15:44
(Original post by ??????????????????)
Risk factors:
-Genetic
-Smoking
-Lack of exercise
-High blood pressure
Smoking causes tar build up in the arteries so they are smaller. This increases pressure. If there are arethroma's in the body, they can become dislodged from the pressure and end up clotting the Coronary arteries which reduced/stop blood flow to the heart so less oxygen. This causes the muscle tissues to die as they have no oxygen to respire with so no ATP produced to contract muscle to the heart tissue dies leading to a MI.
The risk factors involved in CHD include factors such as high blood pressure and high cholesterol, which can be caused by a diet high in salt or saturated fat. High blood pressure can cause the artery walls to weaken and form an aneurysm, whilst high blood cholesterol can result in an atheroma. Smoking contributes to CHD as the nicotine in tobacco increases adrenaline, which results in high blood pressure. The nicotine also has a ‘sticky’ effect meaning red blood cells stick together and form blood clots, which can restrict the blood flow and hence the supply of oxygen to the heart muscle. Smoking also increases carbon monoxide concentration which binds to haemoglobin irreversibly meaning insufficient oxygen is supplied to the heart muscle. These factors result in the heart muscle from dieing, therefore leading to a myocardial infarction. -
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- 15-05-2011 15:44
(Original post by ??????????????????)
Risk factors:
-Genetic
-Smoking
-Lack of exercise
-High blood pressure
Smoking causes tar build up in the arteries so they are smaller. This increases pressure. If there are arethroma's in the body, they can become dislodged from the pressure and end up clotting the Coronary arteries which reduced/stop blood flow to the heart so less oxygen. This causes the muscle tissues to die as they have no oxygen to respire with so no ATP produced to contract muscle to the heart tissue dies leading to a MI. -
??????????????????
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- 15-05-2011 15:44
(Original post by canthardlywait)
Anyone know best way to achieve full marks, when asked to:
-Describe graph
-Explain graph
and also whats the best way to answer an "Evaluate" question.
Any help is much appreciated.
When explaining just say what caused the results.
Evaluate needs both views. Go pros and cons. -
??????????????????
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- 15-05-2011 15:45
(Original post by liviaaa)
I don't think atheroma becomes dislodged? Atheroma is a built up of fatty substances and cholesterol in the lining of the artery, narrowing it. This increases the chance of an embolous getting jammed or a blood clot forming. -
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- 15-05-2011 15:45
(Original post by liviaaa)
Some random Q:
-Define disease
-What's the biochemical test for a lipid?
- What is the role of the nucleus?
i think -
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- 15-05-2011 15:46
(Original post by canthardlywait)
Anyone know best way to achieve full marks, when asked to:
-Describe graph
-Explain graph
and also whats the best way to answer an "Evaluate" question.
Any help is much appreciated.
Explain - say why the described bit ^ happened
Evaluate - the answer is normally no, and it's because it's only a correlation, not cause and effect, so may have been caused my other named factors. (May be yes for once though...) -
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- 15-05-2011 15:47
(Original post by liviaaa)
I don't think atheroma becomes dislodged? Atheroma is a built up of fatty substances and cholesterol in the lining of the artery, narrowing it. This increases the chance of an embolous getting jammed or a blood clot forming.
? i think -
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- 15-05-2011 15:47
(Original post by ??????????????????)
Look up thrombosis. -
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- 15-05-2011 15:48
(Original post by emmaaa65)
an atheroma can rupture and increase the risk of a thrombosis, which can become dislodged and block other arteries
? i think -
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- 15-05-2011 15:49
(Original post by liviaaa)
Thrombosis is the process when a blood clot forms. -
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- 15-05-2011 15:50
Hey
can anyone answer the question in the QP given at the beginning of the thread (11th Jan 2011)
-QUESTION 4 (c) (iii)
It's so confusing!!!!!!! -
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- 15-05-2011 15:50
(Original post by liviaaa)
Yes the blood clot can become dislodged, but not the atheroma I don't think. -
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- 15-05-2011 15:50
(Original post by canthardlywait)
Anyone know best way to achieve full marks, when asked to:
-Describe graph
-Explain graph
and also whats the best way to answer an "Evaluate" question.
Any help is much appreciated. -
??????????????????
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- 15-05-2011 15:51
(Original post by liviaaa)
Yes the blood clot can become dislodged, but not the atheroma I don't think. -
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- 15-05-2011 15:52
(Original post by anna258)
Hey
can anyone answer the question in the QP given at the beginning of the thread (11th Jan 2011)
-QUESTION 4 (c) (iii)
It's so confusing!!!!!!! -
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- 15-05-2011 15:52
(Original post by anna258)
Hey
can anyone answer the question in the QP given at the beginning of the thread (11th Jan 2011)
-QUESTION 4 (c) (iii)
It's so confusing!!!!!!!
basically 1 molecule of water is formed from the condensation reaction between glucose and fructose (therefore making the sucorse molecule needed for olestra to form)
thennnn just count all the letter Rs on the diagram as thats where fatty acids are formed by condensation reactions
there are 8 Rs sooo
8+1 = 9
so the answer is 9
i hoped that helped.. reading back it sounds really confusing -
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- 15-05-2011 15:53
(Original post by liviaaa)
Describe, just say what you see - include figures!
Explain - say why the described bit ^ happened
Evaluate - the answer is normally no, and it's because it's only a correlation, not cause and effect, so may have been caused my other named factors. (May be yes for once though...) -
Ramin Gorji
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- 15-05-2011 15:53
(Original post by EffKayy)
advantages of tem
*small objects can be seen, also internal details
*higher resolution
*small wavelength of electrons
disadvantage
*staining process has to occur, and yet it is still black and white
*2d??
*artefacts may occur from prep.
*has to be in a vacuum
*living specimens cant be tested
*specimen has to be extremely thin
SEM ADVANTAGE - specimen doesnt have to be thin.
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