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    (Original post by ￸￸hi)
    I will weigh in on this matter. I will go through what I put down in the exam to help any efforts to creating a mark scheme, and then I will go through my predictions of what I think the mark scheme will be like (grade boundaries). If someone can remind me of a question I didn't mention here or a question that had not been mentioned before on this thread, I will share my answers and add them to this post.

    My answers:
    • For the very first question about the differences between the bacteria cells and the shown yeast cell, I wrote about the bacteria cell not having a nucleus - that the chromosomal DNA just 'floats around' in the cytoplasm, I wrote that a bacteria cell can sometimes have a flagella and that the yeast cell did not, that a bacteria cell's wall is not made from cellulose and that a bacteria cell does not have a vacuole but the yeast cell does. This question was 2 marks.
    • For the second question I wrote 'mitochondria'. This was a one mark question.
    • For question three, I wrote down 42, although I now believe this to be incorrect. I believe the answer to be 17 or 21. This was a one mark question (I don't know why there is so much controversy surrounding this one mark!).
    • For question 2a the answer was peristalsis. The exact phrase I wrote was: "peristalsis - a wave of muscle contraction", this was to secure the mark. This was a one mark question.
    • For the disadvantage question I wrote that the food had not been churned by the stomach and that the bacteria had not been killed by the stomach acid. This was a one mark question.
    • For the amylase question I wrote the following: "The amylase, a biological enzyme, will break down the starch in the white bread into simple sugars. White bread is easier to break down than brown bread". This was either a two or a three mark question.
    • For the multi-choice fossils question I selected D. This, obviously, was a one mark question.
    • For the question of why the numbers of species A were lessened I wrote the following: a natural disaster such as an ice age, volcanic eruption or an earthquake could have occurred - destroying the habitat, that the species A might have been competing with other species (namely species C) and that the estimates were based on the fossil records - meaning that gaps or decreases in numbers could be due to the fact that some fossils simply had not been discovered yet or were even there in the first place. I'm pretty sure that this question was a three marker.
    • For the question about bases in amino acids, I multiplied the number given by three (because three bases code for an amino acid) to get an answer in the 1800's (don't remember the number exactly). This was a two mark question.
    • For the question about pentadactyl limbs, I wrote that the two bones above the wrist allow for rotation, and that the pentadactyl limb features five fingers. This question was a two or three marker, and because I had just looked at my watch I realised I didn't have much time left so I rushed it.
    • For the question about the DNA from pea cells, I wrote that the first step was required in order to break open the cells and to release the DNA (by breaking open the nucleus). I didn't actually revise the second part of this question (the part about adding in detergent) so I just made up that you are adding biological enzymes to remove unwanted parts of the cell and to soften the DNA. This was a two mark question.
    • For the question about comparing cells produced by mitosis and meiosis, I wrote that mitosis produces two diploid genetically identical cells, whereas meiosis produces four haploid gamete cells. This was a three mark question.
    • For the first circulatory systems question, I can confirm that the answer was the pulmonary vein. This was a one mark question (I think).
    • For the question immediately after the question above, about how de-oxygenated blood moves from the atrium to the lung, I wrote that it goes through the atrium, a valve, then into the ventricle, and then another valve, and that when the heart beats the valves open and the blood moves in a beat. The blood then moves along the pulmonary artery before reaching the lung. This was either a two or a three mark question.
    • For the first six mark question about the blocking of the coronary arteries, I wrote that they can be blocked by excess cholesterol in the blood, meaning that the muscle cells in the heart can't respire as efficiently, meaning a lower cardiac output. To compensate, the heart has to beat faster, which can cause cardiac arrest or a heart attack, and it could even lead to death. I also wrote that the person who suffered from this would suffer from shortness of breath, and that they would build up an oxygen debt very quickly. Another point is that this could cause the heart to beat irregularly, which may cause a stroke. I also wrote that less blood pumping can limit how much other cells can respire because the heart can't supply them with oxygen quickly enough.
    • For the second six mark question I wrote about how the root hair cells of the plant absorb water through osmosis - because the water molecules move from the area of high concentration (soil) to the area of low concentration (root hair cell) through the root hair cell's partially permeable (cell) membrane. I then wrote about transpiration, and how the evaporation of water in the leaves through the stomata causes water to be pulled up from the xylem, which pulls water from the roots. I then compared this chain of transpiration to sucking on a straw. I also talked about active transport, and how it requires energy from respiration, and how osmosis and transpiration require no energy, but I don't think active transport would be on the mark scheme.
    My predictions:
    • I think that the mark scheme will be quite tough for this exam, meaning lower grade boundaries. This test rewarded those who revised, so people who crammed last minute probably won't get a good mark as they probably didn't go into enough detail and they didn't revise all of the topics. Fortunately for people like us that plan ahead, this means that we will probably get higher grades even though we got lower marks. I am personally quite confident that I definitely got an A, and I'm about 70% sure that I got an A*. This is because in the past, the A* boundary has been as low as 45 (!) in March 2013. The A grade was 40 however, and the B grade was 35. This was a difficult paper. However, the June 2012 paper was really a breeze, and when I did it in a home revision session I scored 55 out of 60 marks. The grade boundary here however was 53 marks for an A*, and 46 for an A. This shows that the boundaries can and will vary, and as this was a harder paper I do think that the boundaries will be lower. One reason I think for this paper being harder than the past two years is because Edexcel may be switching to the new GCSE style paper, so that people next year can do our paper and know to expect something similar (this would explain the weird layout and the copious amounts of suggest questions).
    How do you know the grade boundaries are going to be low?
    • Don't worry, if you are browsing this forum it shows that you actually care about your education and grade. You are probably fine and you will probably get an A or an A*.
    • I guess is that the grade boundaries would be similar to March 2013: A* is 45 marks, A is 40 marks, B is 35 marks, and a C is 30 marks.
    • Phew. That's a lot of text I just typed.
    MVP. May I use some answers for the mark scheme?
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    DNA question part (c) was "How did Watson and Crick contribute to the discovery of the structure of DNA?"
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    I got that ! But i have seen a lot of people saying that you had to times the number by three ???
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    Did anyone else do the paper where the article was about a venus flytrap, think it was the IGCSE.
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    (Original post by ARK_REVISES)
    I wrote the same but I think there was two parts to the question. I think how it affects body cells and the heart. So I talked about a lower stroke volume and decrease in cardiac output too.

    I'm not saying it's wrong but I'm defo sure there was 2parts to the question.
    how many marks would i get as
    i talked about how the heart worked harder and so pumps more times per minute increasing heart rate
    also i said it could lead to heart attacks and strokes
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    Hey! Just checking out this thread and I don't think anyone should worry! Science is different from subjects like Maths and does NOT have a set markscheme. You can only guess based on previous markschemes what they would be expecting. If you didn't write the same as someone else, it doesn't mean you are wrong. Edexcel does not DEDUCT marks, they WANT to give you marks. The grade boundaries wouldn't be moderately high if they were marking negatively!


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    hey guys soz, what did you write for that question about why chloroplasts are useful in a plant?
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    If you spelled "peristalsis" which is the right answer as perastalsis would you still get get the mark as i only got one letter wrong
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    could you say disease was a reason for a decrease in population size
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    (Original post by westboy 2016)
    If you spelled "peristalsis" which is the right answer as perastalsis would you still get get the mark as i only got one letter wrong
    99% sure you'd still get the mark, what did you write for that chloroplasts question?
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    (Original post by chelseajabbau)
    99% sure you'd still get the mark, what did you write for that chloroplasts question?
    what was the question
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    what did people get for the embryo and the stem cell question

    i put down:
    that most if not all stem cells in an embryo are unspecialized and so the stem cells divide/differentiate into ant other type of cell in the body.
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    Six marker on how the narrowing of coronary arteries affect the functioning of the heart and surrounding body cells.

    i wrote that less blood will be pumped to the body cells due to narrowing of the coronary arteries. The body cells will therefore receive less oxygen and glucose which is carried in blood and these substances are need for respiration. Due to this the rate of respiration for the body cells will be slower. The heart will also have to work harder. It would have to beat harder and more often to get enough glucose and oxygen to the body cells and so increasing number of beats per minute. With the heart having to work harder and beat more in one minute this may cause heart attacks and stroke.

    how many marks will i get
    i am starting to worry that i answered it incorrectly
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    (Original post by westboy 2016)
    what was the question
    it was asking about why chloroplasts are useful in different parts of the plant i think?
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    (Original post by westboy 2016)
    what did people get for the embryo and the stem cell question

    i put down:
    that most if not all stem cells in an embryo are unspecialized and so the stem cells divide/differentiate into ant other type of cell in the body.
    i talked about cell differentiation and how it can turn into any type of cell - not sure its right tho
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    Edited mark scheme
    Spoiler:
    Show
    Question 1 (Bacterial/Yeast Cell) :
    Part (a):
    (yeast cell)
    • has a nucleus (1)
    • does not have a flagellum(1)
    • does not have a plasmid(1)
    • has a vacuole(1)
    (bacterial cell)
    • has chromosomal DNA /circular DNA (1)
    • has a capsule (1)
    • has a slime coat (1)
    • does not have mitochondria (1)
    Part(b):
    Mitochondria. (1)
    Part(c):
    Question about how anaerobic respiration breaks down to form alcohol and carbon dioxide. Compare anaerobic and aerobic respiration of a yeast cell.
    Correct formula for aerobic respiration (1)
    Part (?):
    The values for the table go from 300 -> 400 -> 200. This shows that the Enzyme activity is reduced below or above the optimum temperature/pH.
    This applies to all enzymes, hence most of their graphs have an upside down U-shape.
    So the value for the sucrose/lactose (can't remember which) will not increase as the values go from 28 -> 35 ->
    It will rather decrease to around (28 -7) = 21. It could be from around 17-21, hence it is that is the correct answer.
    (thanks to TheMasterofLife!)


    Question 2 (Digestion):
    Part (a):
    Peristalsis
    Part(b):
    Disadvantages of using the tube as a model : No villi
    Part (c):
    The amylase in the saliva will break down the starch present in the bread to form sucrose.

    Fossils Question :
    Part(a) :D
    Part (b):
    Human Intervention
    Loss of habitat
    Climate Change
    Predators (correlate to increase in group B&C)
    Part(c):
    • The mammals have a humerus;
    • an ulna
    • wrist bones
    • and 5 fingers/digits. There is more to write, but that should be enough. The other answers are:
    • a radius
    • The wrist bones are called carpals
    DNA Extraction:
    Part(a):
    Part(b):Break up proteins in cell membrane.
    Part(c): Only statement 1 is true
    Part(d):
    Differences between mitosis & meiosis:
    Haploid cells vs Diploid Cells (1)
    Genetically Varied vs Genetically Identical (1)
    4 Daughter Cells vs 2 Daughter Cells (1)

    Circulatory System:

    Part(a):Pulmonary Vein
    Part(b):De-oxygenated blood moves into the right atrium via the vena cava, moves to the right ventricle through the valves, and goes to the lungs via the pulmonary artery.
    Part(c):
    Part(d):Six marker on how the narrowing of coronary arteries affect the functioning of the heart and surrounding body cells.
    • The narrower artery is on the left ventricle. By it being narrow, the muscles receive less oxygen and glucose, and will be worker weaker.
    • The ventricle will not be able to contract as strongly as before, causing less heart pressure
    • This will cause a weaker heart, and decrease the cardiac output
    • This means that the less blood will be going throughout the body, meaning more anaerobic respiration when exercising
    • There will be more lactic acid left over
    • There will be a longer excess post-exercise oxygen consumption (EPOC) (didn't actually write it, just realized it now)
    • Decrease the cardiac output
    • Less oxygen for respiration
    • The heart may not get enought blood causing a Heart attack
    • The person may feel tired/lethargic
    Leaves:

    Part(a):
    Part(b):
    Part(c):
    Light is no longer the limiting factor, and hence, increasing the amount of light intensity will not affect rate of reaction, as some other factor is in shorter supply and is controlling the rate.
    Part (d):
    Six marker on movement of water in a plant.

    Osmosis (1)
    water passes through a partially permeable membrane(1)
    water goes from an area of high concentration to an area of low concentration/diffusion (1)
    water is transported through the Xylem(1)
    Transpiration (1)
    [/QUOTE]

    Edited mark scheme
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    (Original post by westboy 2016)
    how many marks would i get as
    i talked about how the heart worked harder and so pumps more times per minute increasing heart rate
    also i said it could lead to heart attacks and strokes
    Did you talk about diffusion between body cells and capillaries... If u did I am sure u got 6marks. The 6 marks were easy but some dodgy 2-3 markers might put me off
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    (Original post by haybe2k)
    Edited mark scheme
    Spoiler:
    Show
    Question 1 (Bacterial/Yeast Cell) :
    Part (a):
    (yeast cell)
    • has a nucleus (1)
    • does not have a flagellum(1)
    • does not have a plasmid(1)
    • has a vacuole(1)
    (bacterial cell)
    • has chromosomal DNA /circular DNA (1)
    • has a capsule (1)
    • has a slime coat (1)
    • does not have mitochondria (1)
    Part(b):
    Mitochondria. (1)
    Part(c):
    Question about how anaerobic respiration breaks down to form alcohol and carbon dioxide. Compare anaerobic and aerobic respiration of a yeast cell.
    Correct formula for aerobic respiration (1)
    Part (?):
    The values for the table go from 300 -> 400 -> 200. This shows that the Enzyme activity is reduced below or above the optimum temperature/pH.
    This applies to all enzymes, hence most of their graphs have an upside down U-shape.
    So the value for the sucrose/lactose (can't remember which) will not increase as the values go from 28 -> 35 ->
    It will rather decrease to around (28 -7) = 21. It could be from around 17-21, hence it is that is the correct answer.
    (thanks to TheMasterofLife!)


    Question 2 (Digestion):
    Part (a):
    Peristalsis
    Part(b):
    Disadvantages of using the tube as a model : No villi
    Part (c):
    The amylase in the saliva will break down the starch present in the bread to form sucrose.

    Fossils Question :
    Part(a) :D
    Part (b):
    Human Intervention
    Loss of habitat
    Climate Change
    Predators (correlate to increase in group B&C)
    Part(c):
    • The mammals have a humerus;
    • an ulna
    • wrist bones
    • and 5 fingers/digits. There is more to write, but that should be enough. The other answers are:
    • a radius
    • The wrist bones are called carpals
    DNA Extraction:
    Part(a):
    Part(b):Break up proteins in cell membrane.
    Part(c): Only statement 1 is true
    Part(d):
    Differences between mitosis & meiosis:
    Haploid cells vs Diploid Cells (1)
    Genetically Varied vs Genetically Identical (1)
    4 Daughter Cells vs 2 Daughter Cells (1)

    Circulatory System:

    Part(a):Pulmonary Vein
    Part(b):De-oxygenated blood moves into the right atrium via the vena cava, moves to the right ventricle through the valves, and goes to the lungs via the pulmonary artery.
    Part(c):
    Part(d):Six marker on how the narrowing of coronary arteries affect the functioning of the heart and surrounding body cells.
    • The narrower artery is on the left ventricle. By it being narrow, the muscles receive less oxygen and glucose, and will be worker weaker.
    • The ventricle will not be able to contract as strongly as before, causing less heart pressure
    • This will cause a weaker heart, and decrease the cardiac output
    • This means that the less blood will be going throughout the body, meaning more anaerobic respiration when exercising
    • There will be more lactic acid left over
    • There will be a longer excess post-exercise oxygen consumption (EPOC) (didn't actually write it, just realized it now)
    • Decrease the cardiac output
    • Less oxygen for respiration
    • The heart may not get enought blood causing a Heart attack
    • The person may feel tired/lethargic
    Leaves:

    Part(a):
    Part(b):
    Part(c):
    Light is no longer the limiting factor, and hence, increasing the amount of light intensity will not affect rate of reaction, as some other factor is in shorter supply and is controlling the rate.
    Part (d):
    Six marker on movement of water in a plant.

    Osmosis (1)
    water passes through a partially permeable membrane(1)
    water goes from an area of high concentration to an area of low concentration/diffusion (1)
    water is transported through the Xylem(1)
    Transpiration (1)
    Edited mark scheme[/QUOTE]

    Believe me the last question has nothing to do with transpiration and water loss
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    (Original post by ARK_REVISES)
    Edited mark scheme
    Believe me the last question has nothing to do with transpiration and water loss[/QUOTE]

    Yh i agree the last question asked you how does water enter into a plant and how does it travel from roots to rest of plant or something like that. I wrote about osmosis via root hair cells then about xylem vessel, not to sure if you had to mention transpiration anyway because its a loss of water it has nothing to do with water entering a plant, albeit it does create a transpiration stream but still i don't think you necessarily needed to include transpiration.
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    (Original post by zoeolo)
    Hey! Just checking out this thread and I don't think anyone should worry! Science is different from subjects like Maths and does NOT have a set markscheme. You can only guess based on previous markschemes what they would be expecting. If you didn't write the same as someone else, it doesn't mean you are wrong. Edexcel does not DEDUCT marks, they WANT to give you marks. The grade boundaries wouldn't be moderately high if they were marking negatively!


    Posted from TSR Mobile
    Really? so does that mean if you write an answer to a question that is right but isn't on the mark scheme you technically get the marks for it? so does that mean that science oriented examiners will mark our exam? anyway thank you for that you have put my mind at ease.
 
 
 
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