biol+3+trial+exam+analysis

Trial exams play a vital role in further developing your understanding of the concepts and terminology, as well as improving you exam techniques. You have all received 10 exams from 2006-2007. You are not to write on these. Set up a separate workbook for you to write answers, record any questions you have etc. I have plenty more older course exams for you, if you feel you need more practise questions in the lead up to the exam.

Write your analysis of how you went on your first two exams below. You can also use this page to raise any issues or ask questions that directly relate to the trial exams.

Well. I got 100% on both papers. LM How good are you! Perhaps you should teach the class next term and run the revision sessions. VM In general, 'limiting factors' confuse me, as does photosynthesis and cellular respiration. - Q3 a i, ii, iii,b -at the time i was very uncertain about C3, C4 and CAM plants, i have done some revision since then, but this also shows my lack of understanding of photosynthesis -Q. 5iii need to understand more about stomata's functions || MC Q10. Confused? :S Q. 4 Misunderstood the diagram and lost most of the marks here. Q4 C. I don't known was 'coupled reactions' are. Have we covered this? || -MC Q8- Confused. || -MC Q16. Never heard of 'arterial detectors'?? -MC Q19- Confusing? -MC Q22. Need to revis 'melatonin', confused by the graph -Q. 6c. dont fully understand action potentials in relation to the cell being polarised and non-polarised Q 6d- relates to the role of myeline sheath || MC Q14. Confused || MC Q, 20 ||
 * || ** Exam 1-The leading edge  ** || **  Exam 2 IARTV IARTV ** ||
 * The chemical nature of cells || -MC Q4. Relating to movement across the membrane || -MC Q1. Silly mistake, i know RNA is composed of ribose suagr and DNA of deoxyribse sugar ||
 * Enzymes and other biomacromolecules || - Q. 2C- hm..   ||   ||
 * Energy transformation || -MC Q10, My weakest area at the moment is energy transmformations, thus i am struggling to understand what a limiting factor of photosynthesis is.
 * DNA, proteins and proteomes ||  || -MC Q7. This question makes absolutely no sense
 * Homeostasis and regulatory mechansism || -MC Q15. I am still confused by this question. They have a similar diagram on page 102 in the text book and have also referred to it as a proportional control system, i dont understand the different between that and negative feedback system?
 * Detecting and responding to signals ||  || MC Q19.

This is a really indepth analysis and i hope the others use this as a stimulus. You have raised some important points that I will now be able to deal with. VM :-) 

**Q. One of the trial exams asks about CAM photosynthesis. Would you say we'd need to know about CAM plants as well?**

//A. Adpatations that organisms possess to be able to respond to changes in the environment are part of the course. In the current course you only really need to know about PHYSIOLOGICAL adaptations. CAM (crassulacean acid metabolism) photosynthesis is an example that you should be familiar with but only to the extent I have mentioned in the course notes. It is different to C3 and C4 plants in that CO2 is taken up during night (so no water loss) and stored in another form within leaf. Then during day (when sunlight is available and 1st stage can occur) the stomata need not open as the stored carbon is converted back to CO2 to be used for 2nd stage. VM //

Q. There's this multiple choice question which talks about plasmodesmata, and how they are "junctions which exist between cells" which allow plant cells to communicate. Then it asks **which of the following would not be continuous between two adjacent plant cells connected by plasmodesmata: a. //rough ER//, b. //smooth ER//, c. //plasma membrane//, d. //cytosol//.** I know that C & D are continuous (even though I'm still unsure about the wording), but I don't know about the different ER. Has it got something to do with the rough ER being connected to the nuclear envelope and the smooth ER connected to the plasma membrane? I don't know, i think just the wording of this confused me. AP //A. From memory, the question involved a diagram that you need to look at carefully (but I could be totally wrong here). I would think the cytosol and plasma membrane would be continuous between the two. If there was some ER passing through the gap it would be most likely smooth (the picture would have shown no ribosomes on it, if this was the case). You need to be clear on the general role of ER in cells which is the "directed" transport of substances through the cytosol. Rough ER is different in that it has ribsomes attached and therefore is involved in the movement of proteins once they are made and their subsequent 3D nature. Smooth ER is mainly to do with lipid synthesis and other metabolic activities. I don't think the smooth ER would have been connected to the plasma membrane though. Let me know if I haven't explained this OK. VM

//Oh, the question you're referring to i think was on a VCAA exam, and I understood that one i think. This question was on the CSE 2007 exam, and it said **Despite the thick wall of plant cells they are still able to communicate from cell-to-cell. This occurs in virtually all plants via plasmodesmata which are junctions that exist between plant cells.** Then it just asked the question I've bolded (and didn't have a diagram)//. OK, then. Based on that, what I said is still relevant in terms of the role of ER. Although rough ER is generally only found near the nucleus, so your logic was OK. It's not really a good question, given the amount of info they provided you with. I will cover cell communication in plants a bit later on anyway, so don't worry too much about that. VM//

** Exam 2 IARTV IARTV** the answer A: says that RNA will have 15% thymine?!?!?! this obviously cant be right.. unless it is asking something else!?!!? I agree the answer should be D based on the info given. 30% of the bases in the DNA are A, therefore 30% would be uracil in the RNA. VM the answer D: says that the element sulphur could be present in the R group od this molecule BUT.. A says the molecule is a polypeptide made up of amino acid monomers- or can this not be true because there is only 2 monomers aka is it a dipeptide?) Yeah, the term poly refers to many and would not be appropriate for a molecule made up of only two monomers. You should be familiar with the fact that amino acids can contain sulphur and that this would be present in the R-group. Only 2 amino acids have S as part of the monomer make up. VM the answer B: positive feedback mechanism i understand that positive feedback will enhace the stimulus.. but if the stimulus was lowering body temp/heart stoping to beat why would our body enhance this?? or is this just stupid and is something we are just suppose to recognise as a stimulus being enhanced therefore must be positive feedback!?!? This is not a very well constructed or worded question. The positive refers to the temperature and that it is continually dropping. This type of response is dangerous and is what happens when our bodies suffer trauma. It tends to shut down to protect itself and does so in a positive feedback way. A negative feedback (which is what would happen in normal situations) would result in temperature going back up. VM
 * MC-Q7** (i agree with lozz makes no sense)
 * MC-Q4** (shows a diagram of 2 amino acid monomers linked together)
 * MC-Q18** (confused)