2016 B3 unofficial mark scheme aqa 2016

Unofficial ....HIGHER...

Question 1)
a)Diffusio, Active Transport
b) The bag got heavier because osmosis took place as there was a difference in concentration of sugar solutions so water was taken in so the sugar concentrations became equal.
c) Bag B
Because... Smallest difference in sugar conc. so osmosis will take place the least in this one.

Question 2) (I think it... was the lungs ones)
a) Diaphragm flattens....Volume Increases
b) The shape of the alveolus is different ... the person with the problem has disorted shape
bii) this made it difficult for them to breathe while exercising because the surface area is reduced so not the max. volume of air is not drawn in. While exercing the muscles need energy and this comes from respiration (at least for aerobic) And as the person can not supply sufficient oxygen it means respiration is anareobic... And they can only take in short breaths as there isnt much surface area.

Question 3) (The Movement of ions,water and sugar? 6 marker)
Transpiration Water from inside a leaf evaporates and diffuses out of the leaf, mainly through the stomata (tiny holes found mainly on the lower surface of the leaf) This creates a slight shortage of water in the leaf, and so more water is drawn up from the rest of the plant through the xylem vessels to replace it. This in turn means more water is drawn up from the roots, and so there’s a constant transpiration stream of water through the plant. Roots take up ions ) could be though active transport/osmosis/diffusion) and sugars from the soil and the Xylem transports water/minerals up to the leaves. The phloem transports sugars such as sucrose up the stem.

Question 4) (Heart)
a) Artery has thick muscles and small lumen cause the pressure of the blood coming from the heart is high. Veins have less muscles and bigger lumen so it can carry lots of blood and it doesn’t need thick muscles as its going to the heart.
b) The two differences in the blood components are:
1) Artery contains more oxyhaemoglobins but vein has more haemoglobins.
2) I don’t this... But I said they have less plates in the vein because its going to the heart and it is not needed as much than where as in the muscle it is??
Other potential answers:more oxygen and glucose in the artery and more carbon dioxide in the vein.

Question 5) (Deforestation)
a) Pattern: Deforestation has happened around the border, more in the east ... and the south/south west. The west has continued to be cut down.. more than 250 km. The centre has not been affected.
b) Why does it take place?
1) More population so more land needed to live
2) More demands such as more paper needed and timber used for buildings
c) What are the effects on ecosystem?
1) More habitats destroyed so the distributions of organism differ
2) Less biodiversity because animals are killed during trees being burnt

Question 6) (Insulin)
a) Something about pancreas treatment... organ is rejected because the antigens on the organ is not recognised to the white blood cells produce antibodies which attack the organ. It can be reduced by tissue typing or giving drugs to reduce activity of immune system.
b) When the insulin is too high after the meal...
The sensor senses it... sends it to the data which sends it to the phone etc which calculates the dose of insulin...and tells the insulin pump to send it out. Once the insulin is in the blood it makes the glucose in the blood decrease by storing it in the liver/muscle as glycogen.
c) It is better than other method because
The amount of insulin needed is calculated quickly after sensing so it is quicker to get the glucose levels back to normal

Question 7) (Cow meat burger question?)
a) This way is better than normal because...
1) Does not kill the cow so it may be more ethical?
2) More burger made in short period of time than cows which are intensively farmed therefore less likely to get diseases from it?
b) Better for environment something like that?
-Cows produce methane which is a greenhouse gas
-To grow cows you need to heat their environment so fossil fuels are needed
c) Stem cells are undifferentiated cells which can specialise to become potentially any cell in the body.
d) Better to use stem cell from somewhere other than embryos because some people feel that it could have been potential life and it is killing it.

Question 8) (Stomata)
a)Graph: As the stomata increased the conc of CO2 decreased... use some data
b)The CO2 is needed in photosythesis ... But only a certain amount is needed as if there are more stomatas more CO2 will taken in so less conc is needed.
c) Disadvantage of too many: Water vapour will evaporate out at a faster rate.
d) it will be quickest in dry conditions because high conc. in plant low conc. outside so evaporation is quicker.
( I think there was 1 more question on this topic)


Question 9) (Mycoprotein) (4 marks)
A fungus Fusarium is the main source of mycoprotein. The fungus is grown in fermenters glucose syrup as food. The glucose syrup is obtained by digesting maize starch with enzymes.The fungus respires aerobically, so oxygen is supplied, together with nitrogen (as ammonia) and other minerals. The mixture is also kept at the right temperature and pH. It’s important to prevent other microorganisms growing in the fermenter, so the fermenter is initially sterilised using steam. The incoming nutrients are also heat sterilised and the air supply is filtered. Once ready, the mycoprotein is harvested, purified and dried. It’s then processed further by adding flavourings and other ingredients.

.... I don’t know where these answer goes...
-Some thing about blood from protein ?
1) Less likely to be rejected by the body
2) Person does not need to take drugs to reduce activity of immune system so less costly and less likely to get infections.

-How the body responds to decrease in temp:
The blood vessels constrict blood flow so heat isnt lost via heat transfer
Do not sweat so less water is lost as well as heat
Hair sticks up creating an insultating layer
Muscles shiver which gets energy by respiration so heat is transfered
Blood keeps to the core and not the borders such as tips of fingers
Some blood flow maybe cut off from muscle if the decrease is really low to keep the heart warm



I can not remember all the questions... if there are any other please tell me!

Is it not diaphragm contacts which therefore increases the volume in the lungs. I'm pretty sure it is. If it reaxes/fallaterns then the volume will decrease and iar forced out but it was breathing in. Please tell me I'm right someone

Can you say the diaphragm moves downwards?

Is it not diaphragm contacts which therefore increases the volume in the lungs. I'm pretty sure it is. If it reaxes/fallaterns then the volume will decrease and iar forced out but it was breathing in. Please tell me I'm right someone

will it be possible to put the marks next to it ?

Are these all the answers

Youre right but flattens and contracts is the same thing as both increases the volume

Unofficial ....HIGHER...

Question 1)
Question 3) (The Movement of ions,water and sugar? 6 marker)
Transpiration Water from inside a leaf evaporates and diffuses out of the leaf, mainly through the stomata (tiny holes found mainly on the lower surface of the leaf) This creates a slight shortage of water in the leaf, and so more water is drawn up from the rest of the plant through the xylem vessels to replace it. This in turn means more water is drawn up from the roots, and so there’s a constant transpiration stream of water through the plant. Roots take up ions ) could be though active transport/osmosis/diffusion) and sugars from the soil and the Xylem transports water/minerals up to the leaves. The phloem transports sugars such as sucrose up the stem.

I just looked at a mark scheme for a B3 past paper in 2013 which said that the artery contains more carbon dioxide and less oxygen than the vein on question 1 c ii). After doing the paper the night before i put this down in the exam and im sure its right, despite everyone else saying its not . Any help?

I thought the six mark question was about the different components of the blood, not transpiration???

Thanks for this, it's really helpful!
Just going to mention though that phloem transports dissolved sugar from the leaves to the rest of the plant, down the stem, rather than up it (just thought it was worth mentioning because the question asked you to refer to movement up/down specifically). Also, the roots absorb ions by active transport and water by diffusion, but not sugar.
It's so reassuring seeing these answers though!

Thank you

Hi,

The Revision guide for the exam states that the Phloem transports glucose and sucrose up and down the plant.

I think the mark scheme in question is referring to the pulmonary artery, as in, the artery which specifically carries deoxygenated blood from the right side of the heart to the lungs for oxygenation. Therefore, this artery would be an exception to the general rule and contain low levels of oxygen and high levels of carbon dioxide, but the artery in the leg would contain low levels of carbon dioxide as it is carrying oxygenated blood around the body.

Sorry - I did the same thing with that mycoprotein question, blindly stated that 'anaerobic respiration' takes place because that was what I'd incorrectly written on my revision card when the diagram clearly showed aerobic respiration taking place :/ at least it's only one mark

Thanks for this, it's really helpful!
Just going to mention though that phloem transports dissolved sugar from the leaves to the rest of the plant, down the stem, rather than up it (just thought it was worth mentioning because the question asked you to refer to movement up/down specifically). Also, the roots absorb ions by active transport and water by diffusion, but not sugar.
It's so reassuring seeing these answers though!

Thank you

Hi,

The Revision guide for the exam states that the Phloem transports glucose and sucrose up and down the plant.