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Unofficial AQA GCSE Biology Unit One Mark Scheme - 5th June 2013

I have decided to create a new thread for this so I could moderate the answers for the mark scheme - plus I started this mark scheme in the first place. And below is the mark scheme - you can discuss answers below, suggest improvements, or remind us of any questions we've missed. We'll also have to get the number of marks for each question up soon.


Question One

a) Before 1840, death rate remained about the same between both wards. However after 1840, death rate increased in Ward A to 11.4 percent in 1844, but death rate decreased in Ward B to 2.8 percent in 1844.
b) In Ward A, doctors had not washed their hands and so infectious diseases were easily spread within the ward. This meant that death rates increased. In Ward B, nurses had not washed their hands either but they had not came in contact with patients with infectious disease in Ward A. This meant that there was less infectious disease spread around in Ward B as they were not transfered from Ward A and death rates decreased.
c) After docters had been told to wash hands, death rates in Ward A had decreased down to 2.8 percent in 1846 and further down to 2.4 percent in 1847. This shows that washing hands had decreased death rates greatly in a ward with patients carrying infectious diseases.
d) More advanced understanding including in the introduction of vaccines, new medicines discovered


Question Two

a) They should continue their usual diet
b) All three slimming programs had produced an average loss in mass of over 3.5 percent on the first week. However over the next few weeks, the average mass lost decreased more slowly at each progressing week until there had been very little mass lost had there been any on the sixth week.
c) All three slimming programmes had produced an average loss in mass greater than the control group and there had not been any average gain in mass over the six weeks of the investigation.


Question Three

a) Photosynthesis takes in carbon dioxide in the atmosphere into green plant and is then stored as carbohydrates, fats and proteins. When plants respire, carbon dioxide is released back into the atmosphere. When plants are eaten by animals, carbon compounds are transferred into animals and take up the form of fats and proteins. When animals respire, carbon dioxide is released back into the atmosphere. Waste materials excreted from animals also contain carbon. This waste material and dead material from animals that have died are decomposed and decayed by microorganisms. These microorganisms also respire which cause carbon dioxide to be released back into the atmosphere. However, dead plant and animal matter can become fossil fuels, which release carbon back into the atmosphere through combustion.


Question Four

a) Metabolic rate is the speed at which all chemical reactions in the body take place.
b) Physical size, proportion of muscle to fat, inherited factors, age, gender
c) Seventy-seven years


Question Five

a) Cytoplasm, cell membrane
b) Chemical form
c) The bee would have been the stimuli which would have been detected by the eye, which would have been the receptor. An electric impulse is then sent along the sensory neurone to the synapse and effectively the central nervous system. At the synapse, chemicals are released that diffuse across the gap and an electric impulse is then sent along the relay neurone to another synapse. Chemicals are released again and another electric impulse is sent along the motor neurone towards the effector. In this case, the effector would have been a muscle, which would have contracted closing the eye in the response.


Question Six

a) A drug is a substance that alters the body chemistry.
b) I would recommend aspirin. Firstly, it is much less expensive at 15 pounds for aspirin compared to 150 to 500 pounds for statins. It also has an equivalent, if not slightly better, success rate of 31 percent compared to 30 percent that of statins. The downside is that aspirins may increase the chance of blood clots - but statins can cause muscle and liver damage. In conclusion, both drugs have their own side effects but these are kept at a minimum. Aspirin is less expensive than statins but is equivalent in success rate compared to statins - the lower cost option to produce the same results in what both drugs are supposed to do.


Question Seven

a) Auxin allow "rooting compound"
b) Asexual reproduction only involves one parent and the offspring will be genetically identical to it. This is because there is no fusion of gametes and therefore no variation.
c) Plants can be grown all year, there is more space to grow, less chance of catching disease because of sterilised conditions


Question Eight

a) Jean-Baptiste Lamark
b) There was variation in swords in swordfish. Swordfish with shorter swords are not able to defend therefore killed off. Longer sword swordfish able to survive due to high defence, and reproduce, pass on successful characteristic. Eventually, the population of long sworded swordfish would increase. Variation in the length of swords could have been a result of mutations in genes.
c) Experiments did not support Lamark's theory, whilst they did support Darwin's theory. Current knowledge of genes now also support Darwin's theory.


Question Nine

a) Box three disputed box one
b) Temperature had caused faster growth and therefore increased numbers of animal algae, there was more plant plankton to feed on and therefore there was more animal algae as a result - more survived and reproduced raising numbers of animal algae
c) Animal algae feeds on plant algae. Thus as animal algae numbers increase, plant algae levels start to fall.
d) At one point, animal algae levels increased when there was more food. This resulted in more intake of mineral ions by the plankton. But once there was not enough mineral ions, animal algae started to die out. This resulted in mineral ions being released back into the sea. The decrease in both animal and plant plankton in around October meant that concentration of mineral ions in the sea started to increase.

(edited 10 years ago)

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Well I've failed then :/

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Reply 2
Wouldn't question 4b) also be inherited factors??
Reply 3
Original post by Jambon66
Wouldn't question 4b) also be inherited factors??


Added
Reply 4
Thank you for taking your time to make this mark scheme, I know it can be time consuming.
Reply 5
Can you please add the actual questions if possible?
Reply 6
Well this was my question plan, but oh well:

1. Semmelweiss
--------------------------------------------------------------------------------
| [ ] Describe the difference between wards
| [ ] Explain the difference between wards
| [ ] Evidence method had worked
| [ ] Why less death rates today
--------------------------------------------------------------------------------


2. Slimming programmes
--------------------------------------------------------------------------------
| [ ] What should control group eat
| [ ] - Do you remember this question -
| [ ] Describe the effects of slimming programmes
| [ ] Evidence slimming programmes were effective
--------------------------------------------------------------------------------


3. Carbon cycle
--------------------------------------------------------------------------------
| [ ] Describe carbon cycle
--------------------------------------------------------------------------------


4. Metabolic rate
--------------------------------------------------------------------------------
| [ ] What is metabolic rate
| [ ] What factors affect metabolic rate
| [ ] Predicted age of woman before death
| [ ] - Do you remember this question -
--------------------------------------------------------------------------------


5. Nervous system
--------------------------------------------------------------------------------
| [ ] Label the diagram
| [ ] What form of information across junction
| [ ] Describe reflex action
--------------------------------------------------------------------------------


6. Drugs
--------------------------------------------------------------------------------
| [ ] What is a drug
| [ ] Which drug between statins and aspirin would you recommend disadvantages and advantages
--------------------------------------------------------------------------------


7. Asexual reproduction
--------------------------------------------------------------------------------
| [ ] Main characteristics of asexual reproduction
| [ ] - Do you remember this question -
| [ ] Advantages of tissue cultures over plant cuttings
--------------------------------------------------------------------------------


8. Evolution
--------------------------------------------------------------------------------
| [ ] Who made the theory
| [ ] Use natural selection to explain swordfish swords
| [ ] Why was the other scientist's theory not accepted
--------------------------------------------------------------------------------


9. Algae
--------------------------------------------------------------------------------
| [ ] Which pyramid of biomass best represents the decrease
| [ ] Explain changes in animal plankton
| [ ] Explain changes in mineral ion levels
| [ ] - Do you remember this question -
--------------------------------------------------------------------------------
Reply 7
Is it possible to put the amount of marks on the ones you know?
Reply 8
Original post by Jambon66
Is it possible to put the amount of marks on the ones you know?


Don't wanna get any wrong :P

I'll ask my biology teacher to have a look through the question paper again tomorrow.
Reply 9
Original post by Applequestria

Question Nine

a) Box three
b) Temperature had caused faster growth and therefore increased numbers of plant algae.
c) At one point, animal algae levels increased when there was more food. This resulted in more intake of mineral ions. But once there was not enough mineral ions, animal algae started to die out. This resulted in mineral ions being released back into the sea.
d) [Please remind me and suggest answers]



I disagree with question 9.
a)I personally feel it is option one but I accept it could be option 3
b)Temperature had nothing to do with it that was the next question, this was to do with the number of predators i.e. animal plankton.
c)It wasn't to do with animal algae but the temperature and light available.
(edited 10 years ago)
Original post by SportsFan
I disagree with question 9, all of it!


Well at least say why and what you'd put. :/
What do you think is the harshest grade boundary plus out of 10 how difficult was the paper
Reply 12
Original post by Applequestria
Well at least say why and what you'd put. :/


updated
Original post by Miladrises
What do you think is the harshest grade boundary plus out of 10 how difficult was the paper


Harsh:
A* - 48
A - 41
B - 36
C - 26
D - 19

Predicted:
A* - 42
A - 36
B - 29
C - 23
D - 16
Reply 14
Original post by Miladrises
What do you think is the harshest grade boundary plus out of 10 how difficult was the paper


The harshest grade boundary would be something
A* - 49
A - 38
B - 32
C - 26
D - 20
It's definitely possible but unlikely.
Difficulty out of 10: 8/10
(edited 10 years ago)
Original post by SportsFan
I disagree with question 9.
a)I personally feel it is option one but I accept it could be option 3
b)Temperature had nothing to do with it that was the next question, this was to do with the number of predators i.e. animal plankton.
c)It wasn't to do with animal algae but the temperature and light available.


a) There's a dispute going on between box one and box three
b) It asked for you to suggest what had caused an increase in animal plankton - one way of answering is talking about temperature (which had been given on the graph). If you had a different answer, you could've just allowed me to update the mark scheme.
c) This question asked why there was different levels of mineral ions throughout the year.
Reply 16
Original post by Applequestria
a) There's a dispute going on between box one and box three
b) It asked for you to suggest what had caused an increase in animal plankton - one way of answering is talking about temperature (which had been given on the graph). If you had a different answer, you could've just allowed me to update the mark scheme.
c) This question asked why there was different levels of mineral ions throughout the year.


The light and temperature had an effect on the number of minerals.
Original post by SportsFan
The light and temperature had an effect on the number of minerals.


How does that work? :P
I don't recall light and temperature affecting minerals...
Reply 18
Original post by Applequestria
How does that work? :P
I don't recall light and temperature affecting minerals...


Photosynthesis
Original post by SportsFan
Photosynthesis


But it's in the sea, and photosynthesis does not change uptake of mineral ions by the algae.

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