ATAR Notes: Forum
HSC Stuff => HSC Science Stuff => HSC Subjects + Help => HSC Biology => Topic started by: anotherworld2b on July 04, 2016, 12:27:45 pm
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Hi I was wondering if I could get help in answering some questions :)
I've attempted at answering them but I'm unsure whether I am right particularly for Q2.
* Q1
Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. In the small intestine there is high surface area which allows for greater absorption. Which will be absorbed into either lymph or blood vessels. In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood. Lastly, diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal. Concentration difference is maintained through the movement of lacteal in the villi in the small intestine.
* Q2
In doing the wall sit in Activity 11.2, your quadriceps muscle was contracting isometrically. Muscles are also to contract isotonically. Find out the difference between these two types of muscle contraction. Then, using the biceps muscles as an example, describe situations that would result in each of these two types of contraction.
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Hi anotherworld2b,
So far the responses that were given were pretty good, depending on the length of the question (judging by the marks) this is a good start. To improve the answer though to ensure you can get as many marks as possible, try and be more specific with your answer.
Here's some feed back I'd give for your first answer
Concentration difference is maintained in the small intestine which consists of millions of lacteals. In the small intestine there is high surface area which allows for greater absorption This is a good way to explain the absorption of digestive products but you need to be clearer as to WHY this is. So if you explain that the folding of these lacteals allows for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients the answer would be better . Which will be absorbed into either lymph or blood vessels This should be one sentence . In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood. Lastly, diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal Whilst it is good to mention osmosis as a form of passive transport, you also have to state 2 things. 1: Osmosis must occur through a semi-permeable membrane and 2: It occurs in the large intestines mostly . Concentration difference is maintained through the movement of lacteal in the villi in the small intestine. Whilst 'movement' could suffice in answering this question in order to maintain this difference, you should be mentioning the CONSTANT movement of concentrations in order to keep the difference. Also you need to mention that the movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP
For question 2, I'm not quite sure how I would go about asking this question since it seems to be more of a PDHPE question. It might be beneficial to try and post this 2nd question on the PDHPE forum here: Personal Development, Health and Physical Education
Hope this helps you with your questions
Skidous
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The second question is related to pdhpe
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Hi I was wondering if I could get help in answering some questions :)
I've attempted at answering them but I'm unsure whether I am right particularly for Q2.
* Q1
Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. In the small intestine there is high surface area which allows for greater absorption. Which will be absorbed into either lymph or blood vessels. In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood. Lastly, diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal. Concentration difference is maintained through the movement of lacteal in the villi in the small intestine.
* Q2
In doing the wall sit in Activity 11.2, your quadriceps muscle was contracting isometrically. Muscles are also to contract isotonically. Find out the difference between these two types of muscle contraction. Then, using the biceps muscles as an example, describe situations that would result in each of these two types of contraction.
You could also probably give the second question a look online. There's a lot of stuff about how muscles work on YouTube that are pretty good.
Basics though iso=same, metric=length, tonic=tone.
So in the case of biceps:
isometric: let's say someone asks you to put your arms out and passes you a brick. Your arms stay put, but obviously your biceps has to contract to carry the weight of the brick. So it's isometric because the muscle length hasn't changed, but not isotonic because the tone of biceps has increased so as to carry the weight
I'll give you a chance to work out an example of isotonic
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Would this be a better answer? Would it be necessary to mention other parts of the alimentary canal? I
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. Each villus is about 1mm long and is covered by a single layer of cells. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.
In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal. The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.
Absorption is further enhanced by continual movement of the villi brought about by the muscular movements of the intestinal wall. This constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach.
I've tried to answer this question as well?
Q1. In doing the wall sit in Activity 11.2, your quadriceps muscle was contracting isometrically. Muscles are also to contract isotonically. Find out the difference between these two types of muscle contraction. Then, using the biceps muscles as an example, describe situations that would result in each of these two types of contraction.
Isometric contractions is when muscle shortens and movement occurs. Whereas, Isotonic contractions is when muscle does not shorten but tension increases.
Types of Muscle Contraction. An isotonic concentric contraction results in the muscle shortening, an isotonic eccentric contraction results in the muscle lengthening. During an isometric contraction the muscle is under tension but neither shortens, nor lengthens.
One example of a situation where these two types of contractions occur is when you lift a weight/dumbbell.
Isotonic: lifting a dumbell?
Isometric: tension(increase of workload) applied while joint and muscle remains in the same position. Eg. holding a cup and filling it with water. Eg. yoga.
I've also tried to answer this question but I'm not sure whether my assumption is right
Q3. The desert hopping mouse lives on dry seeds and never drinks water. It has extremely long kidney tubules.
From where does the desert hopping, mouse get its water? (refer to chap 6)
Even through the desert hopping mouse lives on only dry seeds the glucose it extracts from its food will inevitably produce water as a byproduct.The desert hopping mouse gets its water as a byproduct of cellular respiration by using the dry seeds it ingests as a source of energy. This enables the desert hopping mouse to get water through cellular respiration.
The equation for respiration:
C6H12O6 + 6O2 6CO2 + 6H2O
Glucose + Oxygen Carbon dioxide + water
How is the desert hopping mouse able to reduce water loss in urine to a minimum?
The desert hopping mouse can reduce water loss in urine to a minimum through its extremely long kidney tubules. These tubules will filter and absorb as much water as possible. The long kidney tubules of the desert hopping mouse is significantly more efficient when compared to human kidney tubules.
Another question:
Q4. At one time. It was believed that disease was caused by ‘bad blood’. Taking large amounts of blood from a patient by bleeding (blood-letting) was widely practised as a cure for disease. Louis XII of France had blood taken 47 times in six months; Louis XV was bled 38 times, and Charles XII of England had blood taken numerous times, even just before his death. Describe some of the effects that the removal of large quantities of blood would have on a patient.
Blood-letting was a common practise in medical history which involved the removal of some of a patient's blood for therapeutic purposes to heal ailments. Some effects of the removal of large quantities of blood on a patient include: weariness and dizziness due to anaemia, fall in blood pressure, people may be tired, short of breath, and pale. These effects occur because due to the removal of large quantities of blood, blood pressure falls because the amount of fluid left in the blood vessels is insufficient. The body’s oxygen supply is drastically reduced because the number of oxygen-carrying red blood cells has decreased so quickly.
If there is extreme blood loss the effects on the patient could be life threatening such as hypovolemic shock or Hemorrhagic Shock.
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Would this be a better answer? Would it be necessary to mention other parts of the alimentary canal? I
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. Each villus is about 1mm long and is covered by a single layer of cells. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.
In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable [...]
yep, lifting a dumbbell is right :)
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Would this be a better answer? Would it be necessary to mention other parts of the alimentary canal? I
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. Each villus is about 1mm long and is covered by a single layer of cells. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.
In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into blood. Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal. The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.
Absorption is further enhanced by continual movement of the villi brought about by the muscular movements of the intestinal wall. This constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach.
I've tried to answer this question as well?
Q1. In doing the wall sit in Activity 11.2, your quadriceps muscle was contracting isometrically. Muscles are also to contract isotonically. Find out the difference between these two types of muscle contraction. Then, using the biceps muscles as an example, describe situations that would result in each of these two types of contraction.
Isometric contractions is when muscle shortens and movement occurs. Whereas, Isotonic contractions is when muscle does not shorten but tension increases.
Types of Muscle Contraction. An isotonic concentric contraction results in the muscle shortening, an isotonic eccentric contraction results in the muscle lengthening. During an isometric contraction the muscle is under tension but neither shortens, nor lengthens.
One example of a situation where these two types of contractions occur is when you lift a weight/dumbbell.
Isotonic: lifting a dumbell?
Isometric: tension(increase of workload) applied while joint and muscle remains in the same position. Eg. holding a cup and filling it with water. Eg. yoga.
I've also tried to answer this question but I'm not sure whether my assumption is right
Q3. The desert hopping mouse lives on dry seeds and never drinks water. It has extremely long kidney tubules.
From where does the desert hopping, mouse get its water? (refer to chap 6)
Even through the desert hopping mouse lives on only dry seeds the glucose it extracts from its food will inevitably produce water as a byproduct.The desert hopping mouse gets its water as a byproduct of cellular respiration by using the dry seeds it ingests as a source of energy. This enables the desert hopping mouse to get water through cellular respiration.
The equation for respiration:
C6H12O6 + 6O2 6CO2 + 6H2O
Glucose + Oxygen Carbon dioxide + water
How is the desert hopping mouse able to reduce water loss in urine to a minimum?
The desert hopping mouse can reduce water loss in urine to a minimum through its extremely long kidney tubules. These tubules will filter and absorb as much water as possible. The long kidney tubules of the desert hopping mouse is significantly more efficient when compared to human kidney tubules.
Another question:
Q4. At one time. It was believed that disease was caused by ‘bad blood’. Taking large amounts of blood from a patient by bleeding (blood-letting) was widely practised as a cure for disease. Louis XII of France had blood taken 47 times in six months; Louis XV was bled 38 times, and Charles XII of England had blood taken numerous times, even just before his death. Describe some of the effects that the removal of large quantities of blood would have on a patient.
Blood-letting was a common practise in medical history which involved the removal of some of a patient's blood for therapeutic purposes to heal ailments. Some effects of the removal of large quantities of blood on a patient include: weariness and dizziness due to anaemia, fall in blood pressure, people may be tired, short of breath, and pale. These effects occur because due to the removal of large quantities of blood, blood pressure falls because the amount of fluid left in the blood vessels is insufficient. The body’s oxygen supply is drastically reduced because the number of oxygen-carrying red blood cells has decreased so quickly.
If there is extreme blood loss the effects on the patient could be life threatening such as hypovolemic shock or Hemorrhagic Shock.
Hey anotherworld2b
Q1 was a very good edit, much better than your first attempt, but you still need to talk about how active transport requires energy to perform the function. You also need to refer to concentration gradients and how the nutrients move along these gradients (passive WITH the gradient, active AGAINST)
For Q3 your equation for respiration is incorrect as it is
C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP (Heat)
This is because if ATP is left out the chemical equation is not correct as respiration is the breakdown of glucose and oxygen to produce energy for metabolic functions.
Q4
You should not only refer to the improved absorption of water due to the longer tubules, you need to reference the increased concentration of the urea in the urine as well as the minimal excretion of urine to preserve as much water as possible.
Q5
You do not need to refer to tiredness if you say it causes weariness, you need to talk about what anemia is, but overall the question is good.
Hope this helps
Skidous
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Hey anotherworld2b
Q1 was a very good edit, much better than your first attempt, but you still need to talk about how active transport requires energy to perform the function. You also need to refer to concentration gradients and how the nutrients move along these gradients (passive WITH the gradient, active AGAINST)
For Q3 your equation for respiration is incorrect as it is
C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP (Heat)
This is because if ATP is left out the chemical equation is not correct as respiration is the breakdown of glucose and oxygen to produce energy for metabolic functions.
Q4
You should not only refer to the improved absorption of water due to the longer tubules, you need to reference the increased concentration of the urea in the urine as well as the minimal excretion of urine to preserve as much water as possible.
Q5
You do not need to refer to tiredness if you say it causes weariness, you need to talk about what anemia is, but overall the question is good.
Hope this helps
Skidous
Thank you so much for your feedback :D
For the active transport requiring energy to perform the function. Would you talk about ATP conversions?
'You also need to refer to concentration gradients and how the nutrients move along these gradients (passive WITH the gradient, active AGAINST)' In regards to this particular aspect I am kind of confused how it works. I know to an extent that fat is passive so it has low gradient? into the lacteal -> lymph?
It is greatly appreciated
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Hey anotherworld2b
Concentration gradients refer to moving from a higher concentration to a lower one (think of the hypotenuse of a right angle triangle, the highest part is higher concentration then lowest end is lower concentration). So for Passive transport the nutrients move along that concentration gradient (High to Low) whereas Active Transport uses ATP to go AGAINST this gradient (low concentration to high). This also occurs for movement of nitrogenous waste out of cells.
As for the ATP conversion you don't really need to refer to that, just as long as you recognize that ATP is used in active transport.
Also you have to specify where the concentration for the fat or other nutrients is high or low (From a high concentration in the lacteal to a lower concentration in the lymph)
Hope that helps out
Skidous
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Hey anotherworld2b
Concentration gradients refer to moving from a higher concentration to a lower one (think of the hypotenuse of a right angle triangle, the highest part is higher concentration then lowest end is lower concentration). So for Passive transport the nutrients move along that concentration gradient (High to Low) whereas Active Transport uses ATP to go AGAINST this gradient (low concentration to high). This also occurs for movement of nitrogenous waste out of cells.
As for the ATP conversion you don't really need to refer to that, just as long as you recognize that ATP is used in active transport.
Also you have to specify where the concentration for the fat or other nutrients is high or low (From a high concentration in the lacteal to a lower concentration in the lymph)
Hope that helps out
Skidous
thank you so much for your help :D
I was wondering could the concentration be maintained by blood as well?
I heard that it could but would it be relevant for how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs? How would this work?
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Hi anotherworld2b
Yes it would be good to talk about how blood maintains the concentration difference. This is because since the blood is constantly flowing towards or away from organs, nutrients is always being absorbed into the blood stream or into the organs. In the case of the alimentary canal, the blood flowing past the canal in the capillaries will maintain the concentration difference as new blood is always being passed by the canal, promoting the transport of nutrients via diffusion and osmosis (or active transport) into the blood so that it can be taken into other parts of the body.
Hope this helps out
Skidous
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Hi anotherworld2b
Yes it would be good to talk about how blood maintains the concentration difference. This is because since the blood is constantly flowing towards or away from organs, nutrients is always being absorbed into the blood stream or into the organs. In the case of the alimentary canal, the blood flowing past the canal in the capillaries will maintain the concentration difference as new blood is always being passed by the canal, promoting the transport of nutrients via diffusion and osmosis (or active transport) into the blood so that it can be taken into other parts of the body.
Hope this helps out
Skidous
Just to add to this.
Such is the bloody flow around the alimentary canal (called the portal system btw), all the stuff that diffuses into the blood is taken away straight away, such that the concentration of the blood remains effectively constant.
You'll see this is a fairly common theme in biology. It's the movement of blood through the lungs that maintains the concentration gradient for oxygen, through the kidneys that allows urine to be concentrated etc etc.
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Just to add to this.
Such is the bloody flow around the alimentary canal (called the portal system btw), all the stuff that diffuses into the blood is taken away straight away, such that the concentration of the blood remains effectively constant.
You'll see this is a fairly common theme in biology. It's the movement of blood through the lungs that maintains the concentration gradient for oxygen, through the kidneys that allows urine to be concentrated etc etc.
I've tried to rewrite my response would this be better? All feedback is appreciated :D
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.
In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into the blood. This is due to using ATP to go against the high concentration of these materials in the blood vessel from the low concentration in the lacteal.
Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal through passive transport from high concentration in the lacteal to a lower concentration in the lymph, The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.
The muscular movements of the intestinal wall constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach. The constant influx of nutrients from the consumption of food ensures that the concentration gradient is maintained as nutrients are diffused from the small intestines into the lacteal. This diffusion occurs due to the high concentration of nutrients in the small intestines diffusion into the lacteal with a low concentration of these nutrients. These nutrients that are diffused into the lacteal are then travel in lymph vesicles to lymph nodes. This ensures that a low concentration of these nutrients is maintained in the villi of the small intestines.
Blood is part of the circulatory system which maintains the concentration difference of substances in the alimentary canal. Blood is constantly circulated towards and away from organs allowing nutrients to be absorbed into organs and waste to be collected from the blood stream. In regards to the alimentary canal new blood is always being passed by the canal in the capillaries allowing the transport of nutrients through diffusion, osmosis and active transport into the blood. This is maintains the concentration of nutrients by the fact that the material diffused into the blood is circulated away and around the body allowing diffusion to occurring constantly retaining a constant concentration of the blood.
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I've tried to rewrite my response would this be better? All feedback is appreciated :D
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.
In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into the blood. This is due to using ATP to go against the high concentration of these materials in the blood vessel from the low concentration in the lacteal.
Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal through passive transport from high concentration in the lacteal to a lower concentration in the lymph, The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.
The muscular movements of the intestinal wall constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach. The constant influx of nutrients from the consumption of food ensures that the concentration gradient is maintained as nutrients are diffused from the small intestines into the lacteal. This diffusion occurs due to the high concentration of nutrients in the small intestines diffusion into the lacteal with a low concentration of these nutrients. These nutrients that are diffused into the lacteal are then travel in lymph vesicles to lymph nodes. This ensures that a low concentration of these nutrients is maintained in the villi of the small intestines.
Blood is part of the circulatory system which maintains the concentration difference of substances in the alimentary canal. Blood is constantly circulated towards and away from organs allowing nutrients to be absorbed into organs and waste to be collected from the blood stream. In regards to the alimentary canal new blood is always being passed by the canal in the capillaries allowing the transport of nutrients through diffusion, osmosis and active transport into the blood. This is maintains the concentration of nutrients by the fact that the material diffused into the blood is circulated away and around the body allowing diffusion to occurring constantly retaining a constant concentration of the blood.
Hey AnotherworldB
This response is MUCH better since the last response, however I do notice that you've done some copy-paste of the information that's been given by both myself and Mr T-Rave. Whilst that is good for the information, it isn't as good in responses if they aren't modified to make the sentences run smoothly. If the sentences don't run smoothly, it may place your response from full marks to just under full marks because it was not as cohesive and coherent as a full mark response should be.
To better this response, it is not about the information but your structure. Depending on the marks allocated to this question, the structure may differ.
If it is a 3-4 mark question, you need to immediately go onto the answer, and be concise with your information and get straight to the point. Unlike English, waffling in Bio will make it seem like you don't understand what is being asked. You should also make distinct arguments in your response, so if you want to talk about passive transport, make 2-3 sentence about passive transport only and then say something along the lines of "Active transport is also used..." and continue with active transport. Ensure that the information your given also links to the question.
5-6 Mark Question require a little more information but the structure is very similar (These are usually Assess or Discuss questions so cause and effect language will be needed and a judgment will be needed [but only for the assess question])
7-8 Mark Questions require planning on the structure and understanding where your information must go and being discerning with what information is relevant and what is not. Sometimes it may be better to draw a table, for this you must remember to use headings and draw a box around the table otherwise you will lose marks (I'm not kidding).
Since this appears to be a 3-4 mark question (since it is explain) I want you to try and condense the information as there is far too much for a 3-4 marker in the HSC or Trials
So try to answer this one without copy-paste from your previous response or the information given here
Explain how the differences in nutrient concentrations ensures that absorption will occurs in the alimentary canal. 4-Marks
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I will rewrite my response following your advice:D
I just wanted to put all the information I've received in one place before I lose track of what to include :)
I really appreciate all the help I've received :D
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I will rewrite my response following your advice:D
I just wanted to put all the information I've received in one place before I lose track of what to include :)
I really appreciate all the help I've received :D
No problem anotherworld2b, that's a good way to get started in bio since it's such a content heavy subject, looking forward to marking the response
See ya soon
Skidous
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No problem anotherworld2b, that's a good way to get started in bio since it's such a content heavy subject, looking forward to marking the response
See ya soon
Skidous
I've tried to rewrite my response :D
I hope its better
Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.
The muscular movements of the intestinal wall constantly brings the villi into contact with different parts of the intestinal contents. These contents are constantly changing as new material is emptied into the small intestine from the stomach. In response to the constant influx of material from the consumption of food passive and active transport will diffuse material across the absorbing surface constantly to maintain the concentration difference.
The concentration difference in the small intestines is maintained by the active and passive transport of materials. Materials such as monosaccharides, amino acids, water soluble vitamins undergo active transport into the blood by using energy in the form of ATP. There is a high concentration of these materials in the blood and low concentration in the lacteal but ATP and active transport allows these materials to go against these concentration gradients.
The concentration difference in parts of the alimentary canal is also maintained by the passive transport of material following the concentration gradient. Water is diffused across the absorbing surface from high concentration in the lacteal to low concentration in the blood vessel by a process called osmosis. Other materials such as fat soluble vitamins, fatty acids and glycerol diffuse across the absorbing surface from high concentration in the lacteal to a lower concentration in the lymph vessel. These substances are then taken to the lymph nodes in the lymph to ensure that a low concentration of these nutrients is maintained in the lymph vessel of the villi in the small intestines.
Blood is part of the circulatory system which maintains the concentration difference of substances in the alimentary canal. Blood is constantly circulated around the body towards and away from organs allowing nutrients to be absorbed into organs and waste to be collected from the blood. New blood that flows through the blood vessel in the villi will prompt the transport of nutrients through passive transport, osmosis and active transport from the villi into the blood. As blood circulates the body constantly the nutrients that diffused into the blood will be taken to organs to be absorbed maintaining a constant concentration difference.
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Hey anotherworld2b
This response was much better than before, all the information was there and it was much more coherent than the last one.
The response itself, however may be too long depending on the marks being allocated, so I think it may be beneficial to answer a question similar to this one but for less marks to work on making the answer more susinct but still coherent with the same amount of information.
Hope this helps
Skidous
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Hey anotherworld2b
This response was much better than before, all the information was there and it was much more coherent than the last one.
The response itself, however may be too long depending on the marks being allocated, so I think it may be beneficial to answer a question similar to this one but for less marks to work on making the answer more susinct but still coherent with the same amount of information.
Hope this helps
Skidous
Thank you for your help :D
I was wondering for this question could I get feedback on whether I am answering it correctly please :)
* Chapter 2 - Question 2
American Dr William Bean studied the growth of his fingernails for 35 years. He filed a horizontal line on his thumbnail just above the cuticle (the strip of skin at the base of the nail). By recording recording how long it took the mark to reach the tip of the thumbnail he was able to calculate the growth rate. He was eventually able to conclude:
‘A 35-year observation of the growth of my nails indicates the slowing of growth with increasing age. The average daily growth of the left thumbnail, for instance, has varied from 0.123mm a day during the first part of the study when I was 32 years of age to 1.1.95mm a day at the age of 67.’
Suggest a hypothesis that Dr Bean was testing
An increase in age will decrease the rate of the growth of nails
Which was the independent variable and which was the dependant variable in this investigation?
Independent variable: age
Dependent variable: the growth of nails
List some of the variables that should have been controlled in Dr Bean’s study
-the size of the horizontal line each day he puts it on his thumbnail
-when he places the horizontal line
-where he places the horizontal line
Describe one source of random error in the investigation
An error in the accuracy of the measurement of the growth of the nail due to the measurement being calculated in millimeters,
Measure the length of your thumbnail. Assume that your thumbnail grows at the same rate as that of the 32-year-old Dr Bean. How long did it take the tip of your thumbnail to grow from the cuticle to its present position?
My nail: 12 mm. Dr Bean’s nail’s growth : 0.123mm.
12/ 1.123 = 97.56 so approximately 98 days
Do you think your fingernails and toenails grow at the same rate? Propose a hypothesis and outline an investigation that you could do to test your hypothesis
I do not think that fingernails and toenails grow at the same rate. I believe that fingernails grow at a faster rate than toenails.
Hypothesis: Over time fingernails will grow at a faster rate than toenails.
Method:
File a horizontal line on his thumbnail just above the cuticle (the strip of skin at the the base of the nail)
Measure the growth of each thumbnail and toenail everyday and record measurement
Record how long it took the mark to reach the tip of the thumbnail
Calculate the growth rate
Repeat step 2-4 over a duration for 4 months
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Hey anotherworld2b
This question is a focus on experimental write-up, which is very easy to get a grasp of.
Your variables are correct but you could add a few more controlled variables such as diet, length of the experiment etc.
Your Hypotheses could be better though, the general structure would be If...(state the independent variable) then...(state the dependent variable) because (state reasoning)
For this example. If nail growth rate decreases with age then the rate of growth of the thumbnails should decrease over time because as the person ages, the metabolic functioning of the body begins to slow down until it stops. (that is due to the fact that all cells in the human body have a set amount of times they will divide before they die)
Your calculation is incorrect due to the fact that it is not written correctly (i did not pull out a calculator to test the result myself) it should be 12/0.123.
The method should be numbered, but the overall method is good.
It's an overall good attempt but can be made better in a few places, mainly in the Hypotheses written so try to improve on those.
Hope this helps
Skidous
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Hey anotherworld2b
This question is a focus on experimental write-up, which is very easy to get a grasp of.
Your variables are correct but you could add a few more controlled variables such as diet, length of the experiment etc.
Your Hypotheses could be better though, the general structure would be If...(state the independent variable) then...(state the dependent variable) because (state reasoning)
For this example. If nail growth rate decreases with age then the rate of growth of the thumbnails should decrease over time because as the person ages, the metabolic functioning of the body begins to slow down until it stops. (that is due to the fact that all cells in the human body have a set amount of times they will divide before they die)
Your calculation is incorrect due to the fact that it is not written correctly (i did not pull out a calculator to test the result myself) it should be 12/0.123.
The method should be numbered, but the overall method is good.
It's an overall good attempt but can be made better in a few places, mainly in the Hypotheses written so try to improve on those.
Hope this helps
Skidous
thank you for your help :D
Would this be better?
Do you think your fingernails and toenails grow at the same rate? Propose a hypothesis and outline an investigation that you could do to test your hypothesis
I do not think that fingernails and toenails grow at the same rate. I believe that fingernails grow at a faster rate than toenails.
Hypothesis: If the rate of growth of fingernails is greater then the rate of growth of toenails will be less.
I wanted to ask for this question. An example I thought about was lifting a dumbbell. But I am not sure where the isometric and isotonic contractions will happen :-\
* Chapter 11 - Q7
In doing the wall sit in Activity 11.2, your quadriceps muscle was contracting isometrically. Muscles are also to contract isotonically. Find out the difference between these two types of muscle contraction. Then, using the biceps muscles as an example, describe situations that would result in each of these two types of contraction.
Isometric contractions is when muscle shortens and movement occurs. Whereas, Isotonic contractions is when muscle does not shorten but tension is applied.
One example of a situation where these two types of contractions occur is when you lift a weight/dumbbell.
Isometric: tension(increase of workload) applied while joint and muscle remains in the same position. Eg. holding a cup and filling it with water. Eg. yoga.
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Hey anotherworld2b
The other hypothesis is not like my one from before, the problem is you're not addressing the variables in your hypothesis, so in this case
Independent Variable: Nail growth of fingernails and toe nails
Dependent Variable: Growth Rate
Try to incorporate those into a hypothesis with some form of reasoning behind it.
As for the second question I'm not sure because it is a PDHPE question and I don't do PDHPE