- The cells membranes of the β cells contain both calcium ion channels and potassium ion channels
- The potassium ion channels are normally open, the calcium ion channels are normally closed. Potassium ions diffuse out of the cell, making the inside more negative; at rest the potential difference across the cell membrane is about -70mV
- When glucose concentrations outside the cell are high, glucose molecules diffuse into the cell
- The glucose is quickly used in metabolism to produce ATP
- The extra ATP causes the potassium channels to close
- The potassium can no longer diffuse out and this alters the potential difference across the cell membrane - it becomes less negative inside.
- This change in potential difference opens the calcium ion channels
- Calcium ions enter the cell and cause the secretion of insulin by making the vesicles containing insulin to move to the cell surface membrane and fuse with it, releasing insulin by exocytosis
Insulin brings about effects that reduce blood glucose concentration.
- If blood glucose levels are too high, insulin is released from the β cells in the islets of Langerhans
- If blood glucose levels are too low, insulin secretion stops.
So there wasn’t a question on Chi Squared. Hardy Weinburg was their weapon of choice.
Nitrogen cycle and an awful lot of ecology questions.
The genetic stuff was nice though, and the 7 mark question on tissue culture.
That 11 mark question on animal behaviour, why thank you OCR.
No brain, body plan or nervous system (apart from those 2 marks on the differences between the CNS and peripheral.)
Nothing huge on clones or mutations either. *sigh*
Stress might. I’m not a mind-reader, (as much as the exam board want me to be, it seems) but these are the things I think might come up this time.
- Protein Synthesis (Transcription, Translation). Will probably be a hefty question carrying a lot of marks.
- Gene Mutations - Point mutations, Insertion / deletion substitutions. Definitions of what they are and asking us to read something. Probably linked to a question on protein synthesis. If that’s the case we’ll probably get synoptic stuff from AS thrown in there too to do with protein structure.
- Body plans. One question is bound to be ‘Which gene controls body plan?’ or something to that effect if it is on there.To which we will all answer ‘HOMEOBOX GENE.’
- Apoptosis and Meiosis. - Meiosis didn’t appear on January 11, so might make an appearance here. Learn what happens in each stage. Might be linked to gene mutations or genetic variation.
- Dominant & recessive genes, gene linkage, epistasis. - Again, not on the January 11. I’m getting a feeling that they missed out a HUGE chunk on genes, ready to ask us this time. LEARN YOUR GENES PEOPLE.
- Chi squared - This is one of the things I haven’t put up here because they give you the formula and all the info in the question. You just need to remember that if it is LOWER than the critical value ACCEPT the null hypothesis. If it is HIGHER, REJECT it.
To reiterate: LOWER = ACCEPT, higher = reject.
- Gene therapy. - Maybe. Probably in conjunction with a question on mutations of genes.
- Anything to do with the nitrogen cycle - Nitrogen fixation, Nitrogen fixing bacteria, Nitrification, Denitrification. May come up with questions on bean sprouts/peas.
- Plant Hormones. - Probably commercial uses, though may just be general uses. Remember that ETHENE CANNOT BE SPRAYED DIRECTLY IT IS A GAS.
- The brain. - One part of a question on January 11 was to identify processes that occurred in parts of the brain. They gave you the processes and the picture of the brain with labels A - E. You picked the letter that fit. That was the only question. I think the brain may come up again, though probably not labeling.
- The nervous system - Will probably be synoptic with F214 material if it does come up. Comparisons between sarcolemma and synapse. Oh how fun.
- Muscles - I have a horrible, horrible gut feeling muscles are going to appear. Probably with something nasty attached, like adrenaline and negative feedback. On January 11 there was a question about the fight or flight response to do with the nervous and endocrine systems. The question was to ‘Describe and explain how the activation of the fight or flight response affects voluntary, involuntary and cardiac muscles.’ Worth a whopping 9 marks. Quite nasty.
- Behaviour - Definitions; innate and learned. Classifying learned behaviours (habituation, imprinting, classical conditioning, operant conditioning, latent (exploratory) learning, insight learning). This did come up briefly (the very last question) in January 11. So I’m not entirely sure if it will appear again. It might do. It might not. Learn the examples in the book for each one though, just in case.
- Primate Behaviour - Again, it appeared briefly (2 marks, part of last question) in January 11. May appear again. Probably about the significance and advantages of social behaviour in gorillas.
- Dopamine - Didn’t appear at all. Probably will get asked on it in conjunction with synoptic stuff from AS about enzymes and enzyme inhibitors.
To conclude: GENES, NITROGEN, PLANT HORMONES, BRAIN / MUSCLES/ NERVOUS SYSTEM, BEHAVIOUR.
It’s only a guess, so please don’t just ignore everything else in the book.