Biology P4: Get Your Pen Ready

First of all, good luck for tomorrow's P6 exam.

Second, let us post more beautiful girls picture (not Reon, Ozawa or Dizon):









Now for the real deal.

Basically the most difficult part in this paper is Part II, which can be surprisingly easy as in our prelim exam. Generally, homeostasis (osmoregulation and blood glucose regulation) is the easiest of all. Why? You mention one condition then you mention the opposite condition then you get a mark or two. Add up the organ and the hormone involved, you get 4 marks. Mention the aftermath, you will get two marks (blood glucose conc. down/water retained). Get it?

The one that gives us a lot of trouble are plant growth regulator (PGH) and our friend Darwin and his theory.

As for PGH, I can't think of any better possible answer other than these:

• Name the hormones and what is the effect
• How does it carry out the effect
• Leaf abscission and apical dominance

Yes, I do realize all of them requires memorizing. So good luck with that. But for some tips, rather than memorizing the steps, try to understand what is really happening. Make a flow chart and try to analyze the function of each hormone.

As for our dearest friend who was stranded in Galapagos Island, my best suggestion is to open wikipedia.org, type his name and just read whatever provided along with the link.

Another good bet is to memorize one type of your preferred sympatric speciation and allopatric speciation. For this reason, I strongly suggest you to read PYP and just take one of the stories. Personally, I find the story about prawn is indeed good.

Another dreaded topic (still from the same guy) is selection and variation. For this two topics, fortunately, the flow answer is always the same. Remember about sickle cell anemia and malaria? Practically, selection and variation question always follow such structure:

• Initially there are two variants (or any number) of phenotype.
• Number of population remain constant/ gene pool remains constant
• Mention about survival of the fittest/competition, depend on question
• Also mention about change in condition or environment
• If they can survive, they will be able to reproduce or the other way round
  
• Those who survive pass on their gene to the next offspring (this phrase never fails to appear in such questions), otherwise they die.
• Such changes happen over time -> result in evolution
• Change in number of gene pool

Those are only guidelines and please do not copy paste above phrases during your exam. Seriously. Above points are only guidelines and may need to be modified when answering question such as artificial selection, importance of variation or roles of human in natural selection.

Personally, I would recommend to take questions regarding ATP production (Kreb's, glycolysis, anaerobic pathway, oxidative phosphorylation), photosynthesis (asking about Calvin Cycle or light-dependent), synaptic transmission, gene technology (recombinant DNA, electrophoresis, PCR, Sanger method) and homeostasis (osmoregulation, blood glucose control). As a general rule, take "how" questions rather than "describe" questions. Think of your answer before you write them. If the questions can be answered in less than 100 words (listing only main points), I say go for it.

Hope this help.



N.B. Above pictures contain one transsexual woman. Do not get infatuated with her unless you accept her whatever she is.