Thursday, 24 November 2016

A Level Thoughts!

I just took my Paper 3 today. I took my Paper 2 a few days ago.

Paper 2 was relatively easy as compared to Paper 3.

Paper 2 was very expected, with most if not all questions being standard questions.
Except for the last question, an essay question which asked:
"Describe how amino acids are joined" [6].

I wrote about the translation process initially as it was a 6m question but on second thought, it didn't include the phrase 'the process', so I'm having second thoughts.
It shouldn't have been about condensation reaction as those types of questions typically are only 2-3 marks.

There was also an inhibitor question, to suggest why penicillin can be used as an inhibitor.
The question provided the structure of the substrate and penicillin, but included that penicillin binds irreversibly.

I wrote competitive inhibitors in the end as I thought they must give the structures with similar structural resemblance for a reason as penicillin could replace the substrate and bind irreversibly to the enzyme's active site(?).

Nonetheless, the other questions were pretty expected.

Paper 3 was tougher, with many questions that needed further thought.
But the following questions are what threw me off a bit.
Explain how genetic counselling benefited from the Human Genome Project. [3]
Explain why scientists have more considerations for the use of mitochondria replacement therapy compared to gene therapy. [3]

The paper had about only 50% standard questions, which was quite a shock compared to previous years, which had around 70% standard questions. Oh well.

Time to prepare for Paper 1 MCQ! (For bio and chem)

Friday, 7 October 2016

Top Scorer in Prelims for Biology!

FOR THE SAKE OF UPDATING THAT E GRADE ON MY LAST POST, here are my Prelim results:

Biology: C

In my school, only 1.0%(round up) of the cohort got grade A/B/C for Biology. That's me.

That's after I got E for Term Exams and S for the Mid Year Exam.

Of course, it was not all me. I went for tuition after I got S because I was so demoralised that this blog didn't even appear in my mind anymore. To be honest, though, the tuition didn't really introduce any new concepts; I had all the information in my school's lecture notes already.

It was the message that the tuition gave me on the first day of tuition:
I can give you all the resources that I have; I'm not holding anything.
However, it is you who need to put in the effort to help yourself improve.
Even just one question a week is sufficient.

Of course, I did some self-reflection and admitted that I did not put in full effort into revision for Biology all these while, ever since I'd gotten a B in JC1 MYE. I thought that the difficulty of JC H2 Biology was that and I had already mastered the studying technique. Turns out, the difficult part is the sheer amount of content.

Hence I worked hard and memorised as much as I can word for word and got a C for Prelims and became the top scorer for Biology for prelims.

It's now 30 days away from the start of the A' levels. My goal for Biology is definitely an A and I will not slack and will work three times as hard as I did for the prelims in order to secure a high A.

Oh yes and I was #3 for H2 Economics in the Prelims too so yeah.

Monday, 11 April 2016

11/4/2016: New Study Plans

I've recently gotten back my Term exam results for Biology.

I got an E.

Honestly, I was not surprised, considering my state of mind during the March holidays before the exam. For the subsequent weeks, I was disappointed at my performance and I didn't really want to touch Biology. However, I understand that I cannot avoid this problem and need to tackle this problem head-on.

I have reflected and pin-pointed on two reasons why I did badly:
1. Did not put in daily effort to memorise content word for word.
2. Did not practise doing questions.

Hence, I came up with new study plans to equip me well in preparation for the next exam, Common Test at the end of April.

TOP SECRET: NEW STUDY PLANS
Common Test Topics: OCPEG, Evolution

1. Memorising Content Word for Word
-Aim to replicate OCPEG contents word-for-word without reference to notes.

2. Practise Doing Questions
-Do all OCPEG TYS questions, checking with LMS answers afterwards.
-Do all evolution TYS questions, checking with LMS answers afterwards.

I do hope that this can help me recover my marks in Biology.

Sunday, 27 March 2016

26/03/2016: NUS Lee Kong Chian Natural History Museum Workshop Throwback!

It has certainly been a rejuvenating break after the Term Exam and it is time to prepare for school! For these subsequent Biology tutorials, we'll be going through the Evolution tutorial. 

This reminds me of the National University of Singapore Lee Kong Chian Natural History Museum Evolution Workshop that our school organised for us. We were quite fortunate as the Singapore whale was set up just a day before we visited, so we were the first few to see it!

Let me bring you through our 3-hour adventure!

Museum Walkthrough
The Singapore Whale: "Jubi Lee"--named after Singapore's SG50 jubilee year
We were greeted by the magnificent display of the Singapore whale. The whale specimen was found in Singapore waters and within 6 months of preparation, it was ready for visitors already! The museum guide told us that if we went closer, we could still smell the skeleton.

Thrash found in Jubi Lee's stomach
What our museum guide told us next was certainly quite horrifying-- four plastic cups and tissue packets were found in the whale's stomach! He informed us that this is what we, humans, are doing to the environment and the marine life. It made us reflect deeply that even as individuals, we still have some degree of responsibility over managing our trash properly.

Pelvic bone of the Singapore Whale
 Can you guess what that bone hanging from the whale's tail is? Nope! It's not its male reproductive organ! It's a female, by the way. It is the whale's pelvic bone! The pelvic bone's function is to connect the spine to the lower limbs, which the whale lacks! Since there is no real need for a pelvic bone, it has evolved to a small size.


Anthropod fossil
 This is an anthropod, an invertebrate animal with an exoskeleton. Here, our guide told us that evolution can give rise to "new" genetic information being formed. This is through chromosomal aberrations that result in duplication of segments of the chromosome, which after further chromosomal aberrations and base-pair substitutions and additions/ deletions, can result in new genetic information being formed.


Tetrapod
 This is a tetrapod, a very important specimen discovered that served as the crucial evidence to the now-accepted fact that humans actually evolved from fish! In fact, all tetrapods are considered "fish", including amphibians, reptiles, birds and mammals!


Specimen 05: Female and Male Spider
This Specimen 05 contains both a male and a female spider! The male spider is very much smaller in size than its female counterpart, due to sexual selection. Can you find the male spider? 
Hint: It's on one of the legs!

The museum walk-through had too many specimens for me to showcase all of them, so I'll just leave you guys to visit it on your own! 

P.S. Our museum guide told us that the feathers of a bird's initial function was for it to keep warm instead of for flight! This struck me deeply because I never knew that a selection pressure can lead to an additional trait!

Hands-on Activity Worksheet
After the museum walk-through, we had a hands-on activity where we analysed animal specimens and did a worksheet.


Hand-drawn anatomical structures of pentadactyl limbs in vertebrates
In this activity, we had to observe the limbs of the specimens, then draw and label parts of the limbs homologous to a human arm. The pentadactyl limbs are that of turtles, bats, and pigeons respectively.

There were 5 activities in total, but I personally felt that this would be the most interesting to showcase because of my drawings! (I'm quite proud of them.)

Conclusion:

That's it! I am quite thankful for my school tutors for giving me the chance to go to the NUS Lee Kong Chian History Museum because it really opened my eyes about evolution! It showed me that organisms all around us are the results over billions of years of evolution and they are pretty darn close to perfection (I think).

Edit:

This is the hands-on activity that we did for 1 out of 2 hours of the workshop.
Disclaimer: I am quite busy in this period of time so I did not check the accuracy of my answers.

 

 

 


Tuesday, 22 March 2016

22/3/2016: Biology Term Exam

Today I had my Term Exam, which tested us on the following chapters:

Chapter 2: DNA & RNA
Chapter 4: OCPEG
Chapter 5: Genetic Basis of Variation
Chapter 6: Cellular Physiology and Biochemistry

What happened:
I have always been a consistent student in biology and never accumulated doubts and misconceptions when I have them. However, recently I am finding some difficulty in memorising the content and regurgitating it during exams and tests. I understand that biology is more of an understanding subject than a memorising one but there are some things that you simply have to memorise.

One question tested me on the gaseous exchange of O2 and CO2 between cellular respiration and photosynthesis within a cell. I understand that this question tests me on the processes that (i) produce O2 and CO2; (ii) makes use of O2 and CO2.


Gaseous Exchange between Respiration and Photosynthesis

All I know about this question is:
1. (i) Produce O2:
Photolysis of water in photosynthesis to produce electrons to replace the electron deficit in photosystems II does produce O2 as well.

2. (ii) Takes in O2:
In cellular respiration, O2 is the final electron acceptor of the electron transport chain and requires O2 in oxidative phosphorylation.

3. (i) Takes in CO2:
CO2 is required in carbon fixation in the Calvin Cycle.

What I completely forgot is:
1. How is CO2 produced in cellular respiration.
2. What exactly happens during carbon fixation in the Calvin Cycle.

I was going to revise my work after I type out my reflection to add on to what I know about the question. However, just after typing, I remembered that:
1. CO2 is produced during link reaction of cellular respiration, and oxidative decarboxylation reactions in Krebs cycle.
I have missed out this point in the exam. I still do not remember what happens during carbon fixation, though.

After revising my work, I realise that:
1. During carbon fixation, CO2 is added to RuBP(5C), catalysed by RuBP carboxylase. It is then split into 3PGA(3C) (3-phosphoglycerate).

My Reflection:
Previously, my methods of studying include memorising the notes in chronological order, something like a story. I feel that this method of studying has limitations such as unconsciously thinking that the content near the end of the notes are less important than that of the start. I think a more effective way of studying is to compartmentalise information.

For example, memorise in terms of O2 and CO2 production and uptake in cellular respiration and photosynthesis, memorise in terms of in which processes are NAD and NADP reduced, in which processes are reduced NAD and reduced NADP oxidised in cellular respiration and photosynthesis.

Monday, 21 March 2016

My Personal H2 Biology Blog

Introduction:
This is my first biology-related blog, and also my first blog. My intention for this blog is for me to maintain an interest in biology and also to help me with my A-level examination 2016. I will be posting personalised summaries, mind-maps, and anything that can help me remember the required content, including very lame jokes.

A bit about me:
I'm currently 18 this year and have mild interest in sciences. I do not know the specific field that I have passion in, but since I am doing relatively well in biology, I am trying to maintain the interest by creating this blog.

Disclaimer:
In the end, I am just a student who still has much to learn. I do not assure that the content in the blog is flawless, but I can assure you that it is to the best of my knowledge. Please feel free to comment on improvements to the content/ format of the blog. In fact, please inform me if any content is incorrect or else I'd think that everything that I have posted are correct! 


Thank you :).