Hope those of you that recently sat Unit 1 found it okay. But whatever happened this week is history now to concentrate on Unit 2. Any ideas of what kinda stuff may come up, although its trickey with so few past papers.
If it asks you about dissociation curves - left = higher affin, right = lower affin, for one mark. Explaining the result e.g releases more o2 into respiring tissues / picks up more in lungs.
They bring in some unit 1 stuff too - remember for enzyme stuff: Change in hydrogen bonds (1) results in a change in tertiary structure (1) substrate cannot bind as active site shape isn't complementary (1) no enzyme-substrate complexes formed (1)
Also, index diversity is likely to come up so know how to do this. I'd also suggest learning plant theory too, as this hasn't been featured on the exam yet.
Gas exchange - They could ask you with a diagram, or more simply just recall such as "Give 2 features of gas exchange in fish and explain how it is efficient". Main points to remember: number in brackets indicate marks given for the content Fish: Countercurrent system - oxygen constantly obtained from the gradient created (2) - blood runs against water so O2 is diffused as gradient is steep. Diffusion gradient or diffusion pathway (1) Occurs across whole gill - large surface area (1) Gill filaments/lamellae - large surface area (2)
Insects: Air enters through spiracles (1) spiracles can open/close - prevents water loss Trachea branch out into tracheoles for large surface area (2) - which means tracheoles located close to cells so most cells can obtain via diffusion? (1) Diffusion gradient created so O2 diffuses out into nearby cells Waxy cuticle on surface prevents water loss via evaporation (1)
I have a selection of questions for the whole topic, in a past paper I have made which has 85 marks and meets various Assessment Objectives. If you would like this, please message me. I haven't compiled the mark scheme yet though
hey, i did this exam in june 2009 and then resat it in january, and so far i don't think anything about the transport of water through plants has come up.. so i'd say that's a definite possibility.
I did the Jan 10 paper as my mock, and antibiotic resistance, meiosis & water transport in plants were all missing from it, so I'm thinking they might come up.
plants, meosis, insects, dna hybridisation, immunological comparisons, antibiotics, impact of agriculture and deforestation, all haven't came up dna, blood vessels, taxonomy, are very common
i think types of vatiation will come up ie. inter and intra specific variation, continuous/discontinuous, and some questions on sampling. also water movement and gas exchange through plants im sure will come up.
plants, meosis, insects, dna hybridisation, immunological comparisons, antibiotics, impact of agriculture and deforestation, all haven't came up dna, blood vessels, taxonomy, are very common
for the immunological comparisons did you learn the method of it? or just that it is one of the things used to help with realationship within organisms?
for the immunological comparisons did you learn the method of it? or just that it is one of the things used to help with realationship within organisms?
If it asks you about dissociation curves - left = higher affin, right = lower affin, for one mark. Explaining the result e.g releases more o2 into respiring tissues / picks up more in lungs.
They bring in some unit 1 stuff too - remember for enzyme stuff: Change in hydrogen bonds (1) results in a change in tertiary structure (1) substrate cannot bind as active site shape isn't complementary (1) no enzyme-substrate complexes formed (1)
Also, index diversity is likely to come up so know how to do this. I'd also suggest learning plant theory too, as this hasn't been featured on the exam yet.
Gas exchange - They could ask you with a diagram, or more simply just recall such as "Give 2 features of gas exchange in fish and explain how it is efficient". Main points to remember: number in brackets indicate marks given for the content Fish: Countercurrent system - oxygen constantly obtained from the gradient created (2) - blood runs against water so O2 is diffused as gradient is steep. Diffusion gradient or diffusion pathway (1) Occurs across whole gill - large surface area (1) Gill filaments/lamellae - large surface area (2)
Insects: Air enters through spiracles (1) spiracles can open/close - prevents water loss Trachea branch out into tracheoles for large surface area (2) - which means tracheoles located close to cells so most cells can obtain via diffusion? (1) Diffusion gradient created so O2 diffuses out into nearby cells Waxy cuticle on surface prevents water loss via evaporation (1)
I have a selection of questions for the whole topic, in a past paper I have made which has 85 marks and meets various Assessment Objectives. If you would like this, please message me. I haven't compiled the mark scheme yet though
This sounds really useful! can you send it to me if pos?