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Biology BY2 unofficial mark scheme 1st June 2015
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{These are the answers that I remember}
Family, (the genus listed), (the species listed)
Closely related where top two (stating genus in brackets and species FULL NAME)
Mechanical digestion= mouth and stomach
Lipase production= pancreas
Protein digestion= stomach
End of carbohydrate digestion= duodenum
Arrow to where tapeworm found= small intestine
Why tapeworm found here?= small intestine is sight of food absorption and thus where most nutrients found, so tapeworm absorb nutrients across body surface
Bile salts emulsify lipids making tiny droplets which increase surface area for lipase action in digestion
Alveoli in microscope= many alveoli have large surface area relative to the body and are thin and permeable allowing oxygen to diffuse as short diffusion path. Alveoli also covered by extensive network of capillaries which cause oxygen from alveolus to diffuse to blood and carbon dioxide vice versa.
Mammal ventilation expiration= external intercostal muscles relax, diaphragm relax, thorax move inward and downward, volume of thorax decreases and pressure in thorax increases as air moves out of lungs
Mammal need ventilation= mammal have a small surface area to volume ratio due to their size and specialised organs causing long diffusion path and ventilation being required for gas exchange
Root hair=thin and large surface area with a lower potential allowing osmosis to occur
Plant tissue for carbon isotope= Phloem tissue (because of translocation in phloem)
Carbohydrate found= sucrose
Radio isotope labelling film= translocation of sucrose and amino acids from leaves to growing parts of plants (not certain of this)
Annelid proof of translocation= (no clue so just guessed) A and B both one hour and translocation to growing parts
Calculation= add 1+2.5=3.5hrs 3.5*60=210minutes 210/cm=cm per minute (think it was the other way around)
Apoplast and symplast= apoplast is cell wall to cell wall and symplast is cytoplasm to cytoplasm or plasmadesmata
How does endodermis build up root pressure in xylem= endodermis cells consist of a waterproof substance called Suberin to form casparian strip which blocks apoplast pathway, allows symplast pathway and causes mineral ions to be actively transported into xylem and water to be transported to xylem via osmosis creating water potential gradient which builds up root pressure causing water to move upwards
Sino atrial node function= transmits electrical impulses across atria causing them to contract simultaneously and impulse is sent down to AVN
Purkinje fibres function= carry electrical impulse sent from AVN and to bundle of his, and send these to base of ventricles which contract base upwards
Pressure seconds on graph = 0.6s and 0.3s (guessed)
Letters on graph= B, D, A (guessed)
Why blood doesn't flow from left ventricle back to left atrium= because of the bicuspid valves which prevent the back flow of blood back to the left atrium by closing the valves
Ten marker=
haemoglobin=
-haemoglobin is pigment found in red blood cells
-haemoglobin structure quaternary consists of 4 polypeptide chains of two alpha and two beta
-haemoglobin in mammal carried in blood vessel where closed circulatory system
-in mammal, haemoglobin loaded with oxygen in lungs where partial pressure is high and unloads oxygen in muscle tissue where partial pressure is low
-partial pressure and oxygen saturation represented in oxygen dissociation curve (drawn) which has sigmoidal shape
-llama and lug worm in environments with low oxygen concentrations, llama has more red blood cells to compensate for this and lugworm pumps water from bellow to get dissolved oxygen, both have low affinity of oxygen
-when exercise partial pressure decreases considerably, myoglobin required
-carbon dioxide combines with haemoglobin to form carbamino haemoglobin
Family, (the genus listed), (the species listed)
Closely related where top two (stating genus in brackets and species FULL NAME)
Mechanical digestion= mouth and stomach
Lipase production= pancreas
Protein digestion= stomach
End of carbohydrate digestion= duodenum
Arrow to where tapeworm found= small intestine
Why tapeworm found here?= small intestine is sight of food absorption and thus where most nutrients found, so tapeworm absorb nutrients across body surface
Bile salts emulsify lipids making tiny droplets which increase surface area for lipase action in digestion
Alveoli in microscope= many alveoli have large surface area relative to the body and are thin and permeable allowing oxygen to diffuse as short diffusion path. Alveoli also covered by extensive network of capillaries which cause oxygen from alveolus to diffuse to blood and carbon dioxide vice versa.
Mammal ventilation expiration= external intercostal muscles relax, diaphragm relax, thorax move inward and downward, volume of thorax decreases and pressure in thorax increases as air moves out of lungs
Mammal need ventilation= mammal have a small surface area to volume ratio due to their size and specialised organs causing long diffusion path and ventilation being required for gas exchange
Root hair=thin and large surface area with a lower potential allowing osmosis to occur
Plant tissue for carbon isotope= Phloem tissue (because of translocation in phloem)
Carbohydrate found= sucrose
Radio isotope labelling film= translocation of sucrose and amino acids from leaves to growing parts of plants (not certain of this)
Annelid proof of translocation= (no clue so just guessed) A and B both one hour and translocation to growing parts
Calculation= add 1+2.5=3.5hrs 3.5*60=210minutes 210/cm=cm per minute (think it was the other way around)
Apoplast and symplast= apoplast is cell wall to cell wall and symplast is cytoplasm to cytoplasm or plasmadesmata
How does endodermis build up root pressure in xylem= endodermis cells consist of a waterproof substance called Suberin to form casparian strip which blocks apoplast pathway, allows symplast pathway and causes mineral ions to be actively transported into xylem and water to be transported to xylem via osmosis creating water potential gradient which builds up root pressure causing water to move upwards
Sino atrial node function= transmits electrical impulses across atria causing them to contract simultaneously and impulse is sent down to AVN
Purkinje fibres function= carry electrical impulse sent from AVN and to bundle of his, and send these to base of ventricles which contract base upwards
Pressure seconds on graph = 0.6s and 0.3s (guessed)
Letters on graph= B, D, A (guessed)
Why blood doesn't flow from left ventricle back to left atrium= because of the bicuspid valves which prevent the back flow of blood back to the left atrium by closing the valves
Ten marker=
haemoglobin=
-haemoglobin is pigment found in red blood cells
-haemoglobin structure quaternary consists of 4 polypeptide chains of two alpha and two beta
-haemoglobin in mammal carried in blood vessel where closed circulatory system
-in mammal, haemoglobin loaded with oxygen in lungs where partial pressure is high and unloads oxygen in muscle tissue where partial pressure is low
-partial pressure and oxygen saturation represented in oxygen dissociation curve (drawn) which has sigmoidal shape
-llama and lug worm in environments with low oxygen concentrations, llama has more red blood cells to compensate for this and lugworm pumps water from bellow to get dissolved oxygen, both have low affinity of oxygen
-when exercise partial pressure decreases considerably, myoglobin required
-carbon dioxide combines with haemoglobin to form carbamino haemoglobin
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#2
Parasites do not use their suckers to obtain nutrition, they use it to hold onto the gut (along with hooks). They diffuse the pre-absorbed food through their bodies.
Purkinje fibres only pick up the impulse at the apex, at the bottom of the bundle of His.
Evidence for bi-directional flow was that radioactive carbon was found both above and below the leaf that was provided with radioactive carbon dioxide.
Just a few minor points I could think of
Purkinje fibres only pick up the impulse at the apex, at the bottom of the bundle of His.
Evidence for bi-directional flow was that radioactive carbon was found both above and below the leaf that was provided with radioactive carbon dioxide.
Just a few minor points I could think of
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(Original post by Sophie_Lester)
Parasites do not use their suckers to obtain nutrition, they use it to hold onto the gut (along with hooks). They diffuse the pre-absorbed food through their bodies.
Purkinje fibres only pick up the impulse at the apex, at the bottom of the bundle of His.
Evidence for bi-directional flow was that radioactive carbon was found both above and below the leaf that was provided with radioactive carbon dioxide.
Just a few minor points I could think of
Parasites do not use their suckers to obtain nutrition, they use it to hold onto the gut (along with hooks). They diffuse the pre-absorbed food through their bodies.
Purkinje fibres only pick up the impulse at the apex, at the bottom of the bundle of His.
Evidence for bi-directional flow was that radioactive carbon was found both above and below the leaf that was provided with radioactive carbon dioxide.
Just a few minor points I could think of
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#4
how many marks were there when talking about mammals needed a complex ventilation.mechanism ? and did you have to mention sa to volume ratio ?
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(Original post by sophialouise)
how many marks were there when talking about mammals needed a complex ventilation.mechanism ? and did you have to mention sa to volume ratio ?
how many marks were there when talking about mammals needed a complex ventilation.mechanism ? and did you have to mention sa to volume ratio ?
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#6
(Original post by SalmanOrange)
Yeah I meant absorb, sorry typo. Also, the Purkinje fibres do carry the impulses, search the function on Google
Yeah I meant absorb, sorry typo. Also, the Purkinje fibres do carry the impulses, search the function on Google
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#7
(Original post by SalmanOrange)
I think it was 2 or 3 marks, and I guess you would to explain why they would need a complex ventilation. Don't sweat it only one mark hopefully grade boundaries are low
I think it was 2 or 3 marks, and I guess you would to explain why they would need a complex ventilation. Don't sweat it only one mark hopefully grade boundaries are low
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#9
(Original post by SalmanOrange)
I think it was 2 or 3 marks, and I guess you would to explain why they would need a complex ventilation. Don't sweat it only one mark hopefully grade boundaries are low
I think it was 2 or 3 marks, and I guess you would to explain why they would need a complex ventilation. Don't sweat it only one mark hopefully grade boundaries are low
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#10
(Original post by sophialouise)
how many marks were there when talking about mammals needed a complex ventilation.mechanism ? and did you have to mention sa to volume ratio ?
how many marks were there when talking about mammals needed a complex ventilation.mechanism ? and did you have to mention sa to volume ratio ?
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#11
(Original post by Z1228)
Was the graph one not 0.2 and then 0.6 and also the phases were A C E?
Was the graph one not 0.2 and then 0.6 and also the phases were A C E?
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#12
Can anyone remember what the question said where we had to name something about photosynthesis site and sucrose?
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(Original post by Sophie_Lester)
They do carry impulses, but not from the AVN, it is picked up from the bundle of His
They do carry impulses, but not from the AVN, it is picked up from the bundle of His
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(Original post by sophialouise)
i put large sa to.volum ratio by accident but then i explained everything.else correctly. hopefully ill only loose 1 mark on that . im hoping the boundaries are around 52 for an A.
i put large sa to.volum ratio by accident but then i explained everything.else correctly. hopefully ill only loose 1 mark on that . im hoping the boundaries are around 52 for an A.
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#15
(Original post by Eleanor303)
Can anyone remember what the question said where we had to name something about photosynthesis site and sucrose?
Can anyone remember what the question said where we had to name something about photosynthesis site and sucrose?
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#17
(Original post by jarvisg18)
Im sure the rate was 0.422222222? Please someone?
Im sure the rate was 0.422222222? Please someone?
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#18
(Original post by hprynne)
Agreed! Moved up 38 cm in one and a half hours, convert to minutes is 90. Then 38/90! Most people I spoke to also got 0.422222....
Agreed! Moved up 38 cm in one and a half hours, convert to minutes is 90. Then 38/90! Most people I spoke to also got 0.422222....
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#19
(Original post by hprynne)
Agreed! Moved up 38 cm in one and a half hours, convert to minutes is 90. Then 38/90! Most people I spoke to also got 0.422222....
Agreed! Moved up 38 cm in one and a half hours, convert to minutes is 90. Then 38/90! Most people I spoke to also got 0.422222....
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