In this post, I will seek to address the question whether one should do H1 or H2 biology for the Singaporean A levels. H1 or H2 biology ⌲ an overview In simplistic terms, H1 or H2 subjects differ in their coverage. Where, H2 subjects covers far more content even though the difficulty is the same across H1 or H2 biology. H1 or H2 biology ⌲ considerations Since there is a significant reduction of coverage in H1, this can be useful for those in Arts stream who is interested in the subject, as well as satisfying the contrasting subject requirement. This does not however, rule out the more ambitious Arts stream students who would like to do 4H2 subjects, using H2 biology as a contrasting subject instead. Conversely, H2 biology is the choice for science stream students who are deeply interested in the subject as well as using it as one of the minimum 3, H2 subject requirement. Especially if they do not like Physics. Few science stream students will opt for H1 biology unless they find that they are struggling and not doing well. This in turn is mainly due to the poor school environment for the subject. This is because, most of them are doing the contrasting subject at H1 level and therefore have to do H2 biology to satisfy the minimum 3 H2 requirement. H1 will have less detailed coverage and as a H2 biology tutor, I feel that students may not get the entire picture and hence understanding. For example in the topic diversity and evolution, whilst H1 students will learn about the environmental factors implicating natural selection, there is no continuation about the beauty of environment’s role in speciation. Leading to a somewhat patchy overview of this amazing topic. H1 or H2 biology ⌲ content coverage There is indeed significant reduction in H1 biology in comparison to H2. This can be an advantage especially considering JC life is hectic, and there are no significant advantage for students taking 4 H2 subjects including biology. There are 4 cores in H2 biology (the cells and biomolecules of life | Genetics and Inheritance | Energy and equilibrium | Biological evolution) and 2 extension topics (Infectious diseases | climate change). In H1 biology, each of the cores sees reduction in learning outcomes. Notably all mentions of microorganisms (bacteria and viruses) are removed as well as molecular techniques. In addition, infectious diseases as an extension topic is also out. These topics are some of the most relevant and interesting aspects of biology especially considering the current times. Exams format differences The best part about H1 biology is the exams! Whilst the H2 biology exam is comprehensive (paper 1/2/3+5), H1 biology exams comprises only P1 and 2. P1 comprises MCQs whilst P2 comprises structure and essay questions. This format is more reminiscent of the old format of H2 biology P2 prior to 2017. Since there are no long stimulus questions and integrative style essay questions of P3 in the H2 biology syllabus, this is a big relief to exam taking students since they are comparatively harder. Bottomline I hope I have given you at the very least another perspective answering your question, ‘H1 or H2 biology for A levels (Singapore)’. Most importantly I hope you find exam success in the near future. Finally, let me know if this has been useful.

More from byang

How to find motivation during exam preparation Many students quickly lose steam during exam preparations. I am going to suggest a way to very quickly help you find motivation during exam preparation in such trying circumstances. Why you need to find motivation during exam preparation In my years of teaching, I have seen many students start out strong but quickly fizzle out in the journey to big exams. Not only do they lose appetite for the final preparations, worse still they begin forgetting concepts. This then creates a snowball effect. Where he/she sees that they are not ready for the exams and as a result begin telling themselves negative things. Which in turn further aggravates the preparations until finally, they give up altogether. Students who are suffering in this manner need to quickly get out of the funk in order to get on with the exam preparations. So that they can go on to achieve the grades they want on the graduation transcript. Which in turn open doors either to university admissions or for them to proceed on to the next stage of their life certification in hand. And I am writing this to help you find motivation during exam preparation. Ask yourself WHY?! Ironically, and most importantly the first step to beating self defeat and find motivation during exam preparation is to ask the question WHY? Why are you doing what you are doing now. A lot of students do not start out defining their reasons, instead, they plod through the motion of education. Frequently, the students are not able to muster much if any enthusiasm for life. Worse still, there’s nothing they can look forward to after graduation. Conversely, defining the reasons why you are doing what you are doing helps you to generate the motivation to tide through the pain you are suffering right this moment. It makes the journey through the exams a little better. As a result, that will start a positive feedback loop beating out the downward spiral. However, you will need guidance to properly define your reasons of why you are doing what you are doing. 7 questions of WHY, to find motivation during exam preparation It’s very easy to come up with a politically correct answer for yourself. In addition, your first answer is one that is usually a reflection of the other people’s reasons. This reason may be real but will not generate the motivation you need to push through the difficult period. Because this does not come from a place of desperation since you do not personally identify from it. Let me explain my with example. In friends ask me right now why I am doing what I am doing providing H2 Biology tuition. My standard answer will be that I have seen students suffer in school with lousy instructions in school. Therefore I want to help my students gain subject mastery and lift them out of their misery and find some direction in life. It sounds great right? And this is something I truly believe in as well since I have been doing this since 2004. However, this is not intrinsically motivating to me. This is because the students are in their moment of desperation trying to get through exams. Not me. As such, you have got to continue the line of asking why after the first reason. Like in my circumstance, ‘why do you want to help your students gain subject mastery and …’ Usually by the 5th time of the question, the answer becomes more and more desperate as you dribble down 2 times more. By the 7th WHY question, you will have found your reason and true motivation. Remember the story of a desperate mother successfully lifting a 1400kg car to free her pinned child? Desperation can create immense strength and motivation. Precisely the solution to blast you off to the moon during exam preparations. Let me tell you my reason. My true reason for doing what I am doing Back when I am teaching in school, I hit a ceiling in my teaching career. Even though I have made tremendous strides, I was refused promotion because it was not my time yet. Why did I want to keep pushing on even as a young person who has just started his teaching career? I remember even to this day an event when I was primary 1 that is permanently etched in my mind. It was a huge quarrel between my parents. My father who visits us from time to time alternating between his 2 families decided he had enough and he decided to go back to the other family. (Yes, I grew up knowing that I was a bastard) That’s not before my mum who packed up her bags screaming that she is going to leave first. I was tugging and pulling both of them at their legs. At that moment, what I felt was extreme fear. What am I going to do, all alone, no support, no money, no NOTHING. Zilch. From that moment on, I learnt I need to become self independent. I need to be on top of my game and become resource rich. With that mentality, I left the cushy school teacher job, joined startups to gain the skillset needed to open my own business and finally be in the position where I can help my students gain subject mastery and direction in life by offering H2 Biology tuition. Every time, I lack motivation, I relive the frightening event and am quivering a little as I write this. What if you cannot find that reason? In the past when I do the exercise with my students, some say that they cannot find such a reason. Such are the times of prosperity that we live in! Then let me help you create one. The next time you go to the toilet to take a dump, I want you to imagine the toilet handle is gone. Instead, you have a weak shower head to flush off the pile of foul smelling shit in the toilet bowl. Unfortunately, you cannot leave until you have sorted out and someone is knocking on the door urgently wanting in so that they can take a dump. How do you feel? Anxious? Extreme embarrassment? Wishing you were not there? Praying that you were dreaming? What if this is something that you have to content with for life? Do this for real and you have a strong reason to help find motivation during exam preparation! Find motivation during exam preparation – bottomline I know you are not going to unsee the picture above. But still, the dramatic effect is pertinent to bring my point across and to help you quickly find motivation during exam preparation. This is because time is running out and you need to have every minute ahead of you used productively. I wish you every success in your upcoming exams and you can check out other tips in the section below.
COVID-19 basics for the H2 Biology student Coronavirus whose origins in the city of Wuhan, Hubei province of China is now COVID-19. This virus have quite the profile that spread mass panic all over the world in a very short time. As such, I hope to educate all on the COVID-19 basics so that all my students can see how it relates to their syllabus. More importantly gain knowledge of this virus so as to make sense of the a barrage of news articles and different fallacies from fact. COVID-19 basics: What is it? This is the viral disease that is a result of infection with the novel coronavirus originating from Wuhan. Some scientists are also referring to the same virus as 2019-nCoV or SARS-CoV-2. The virus belongs to the family of viruses which we refer to as Coronaviridae. This virus, like all other viruses contradict the cell theory, which is also why the viral name do not follow the standard binomial naming conventions. Generally, viruses falling into this family have an envelope as well as a positive sense, ssRNA genome. Let me explain the structures and in addition, show you how they look like under the electron microscope. The envelope is the membrane that originates from the host as new virus particles buds out of the host in a bid to release themselves to infect other hosts. They do so because they cannot replicate independently and require the host cell’s replicative machinery. And this method of reproduction is also why disease arise. This is because the target cells of the the novel coronavirus are respiratory cells. Consequently the host respiratory cells can be overcome by virus reproduction resulting in the death of the cells. Remember, these cells play an important role in respiration. Consequently the lost of which would mean they cannot breath properly. Severe lost of the function can then lead to death. Let’s go on to talk about the genome so that we can begin to understand the behavior of this virus. COVID-19 basics: Genome behavior We describe the genome of the virus as positive sense, ssRNA. This means that the genetic material this virus carries is single strand RNA, which is a template for conversion to viral proteins directly. In contrast, the negative sense means that the RNA have to first undergo an additional step of conversion before the RNA can be a template to convert to viral proteins. Unfortunately, this has significant implications when it comes to the potential severity of COVID-19, as we discuss the COVID-19 basics. Firstly, this may explain the speed at which the virus spreads since the synthesis of viral proteins is much faster even though there is no signs of infection yet. Secondly, all RNA viruses have a viral gene that codes for an enzyme RNA-dependent RNA polymerase. This is because that is one enzyme the host do not have since the host do not depend on RNA as genetic material (hosts use DNA instead). The problem with the viral RNA-dependent RNA polymerase is that is lacks the ability to do proof reading. Proof-reading is the mechanism that corrects any errors arising from the replication of genetic material. Errors gives rise to mutations. This ensures a low incidence of mutations that can potentially arise from replication in humans. Increases in mutation results in cancer and other genetic diseases. Consequently this will mean that the novel coronavirus has the ability to change over time leading to a slightly different version of viral proteins. Scientists call this antigenic drift. COVID-19 basics: antigenic drift and human immunology Immunology is the study of an immune response against foreign bodies. In this case, the human immune response can eliminate the novel coronavirus by recognizing specific structures on the virus envelope. This is because viruses have specific structures on them that makes them unique much like we and our fingerprints. The problem arises due to antigenic drift. If the virus changes the specific structures on their envelope, the immune response may not kick in or be less effective recognizing the viruses. In order for them to regain the recognition, the cells of the immune response (specifically T and B cells), has to take time to learn. Since the viral replication continues unabated, it can overwhelm the host before we can fight back by producing the new version of the immune response to the new version of the novel coronavirus. This may likely be the reason why it seems that Wuhan, Hubei has such severe cases not seen elsewhere in the world. At the time of writing, there are only 1 death outside of China (not including 1 death in Hong Kong). The viruses there have undergone antigenic drift. The 1st version of the viruses is the one that the is being spread outside of China. And many are worried the moment antigenic drift occurs that can potentially lead to a wave of deaths we see in China. COVID-19 basics: how do we compare this to Influenza virus Even though there is similar behaviors between the novel coronavirus and Influenza virus, these are 2 very different viruses. Influenza virus has segmented, negative sense, ssRNA genomes. They belong to another family of viruses known as Orthomyxoviridae. It is because they infect the same target host cells and are spread in the same way that’s why it leads to confusion about these viruses. However, there are some differences in the disease though the discussion will be outside the scope here. Influenza viruses too have in the past led to devastating pandemics the last of which was around 1918 killing tens of millions of people. This has been repeating every 100 years and many are wondering if this time the novel coronavirus is it. Influenza virus genome in contrast have segmentation meaning their genes are on 8 different pieces of ssRNA. This unique feature means that if 2 different strains of virus co-infects a human then they can produce a new hybrid of the 2 virus (a swine and a human virus for example). This new hybrid virus may be so different the immune system completely loses the ability to detect and eradicate it leading to disease and spread. Scientist refer to the phenomenon as antigenic shift. In theory this makes Influenza viruses an even more potent pathogen. But it is also a sobering fact that we are living in a time where we have to monitor the ever evolving and increasing number of viral threats. COVID-19 basics: how it spreads Since we have an immediate threat of the novel coronavirus I will focus on the discussion of this virus instead. The respiratory virus can jump from one host to the next easily. This can be via direct contact transmission of which there are 3 ways. Direct (touch, kissing), indirect (touching fomites containing the virus) and droplet (result of talking, sneezing, coughing). At the moment we do not know much about this virus and some scientists suggest there may be other ways of spreading. The discussion of them is outside the scope of this article. As such if one practices personal hygiene and employing protective measures they may reduce chances of becoming infected. The natural next question is why don’t we know about this virus? novel coronavirus The most straight forward answer is that these viruses do not originate from nor use humans as host. Recently, China scientists who have samples of the virus have subject it to phylogenetic analysis revealing that it may have come from Pangolins. Please note, I cannot confirm the validity of this observation as no other scientist outside of China currently have access to the data to confirm this. If true, this differs from the SARS virus which is another related virus from the same family originating from bats. It is likely however that the passing of these viruses from the original animals is due to the close human contact. Which in this case is the hunting, trading as well as slaughtering of this animals for eventual consumption. By chance, this interaction is successful allowing the virus to replicate. As they do so, antigenic drift may occur allowing new viruses to be even more successful at infecting humans. This follows natural selection where the more successful progeny viruses are advantaged since as they increase in numbers faster than those other viruses that have not undergone the same antigenic drift. Consequently, this leads to human to human transmission which we are currently observing. Bottom-line I hope you have a much better idea of COVID-19 basics and the many areas that relate to H2 biology syllabus. Although we are experiencing this epidemic in Singapore, my hope is that it can be curtailed so that our lives can return back to normal finally. Do you have any questions pertaining to this virus? If so, let me know!
Foods that boost learning or exam preparations Many students focus on cramming content in the hopes of boosting their scores for assessments without realising that they can get a bit of help from foods that boost learning or exam preparations. Why use foods that boost learning or exam preparations You are already eating everyday, why not fine tune what you consume with foods that boost learning or exam preparations in order to get yourself that bit of edge versus your compatriots? This can also be in addition to many of these foods having other positive effects on the body. Foods I am going to list contains certain chemicals, which correlates with increase in cognitive performance. Since these are natural components of food, it has little side effects and are also affordable. However, please consult your doctor or dietitian especially to determine if you have any allergies before incorporating any of them. Foods that boost learning: caffeine Caffeine is one of the most important chemicals in foods that boost learning by increasing cognitive and physical performance. Drinks rich in caffeine such as coffee is not surprisingly most commonly drunk for students seeking that increase in cognitive performance. Let me simplify the biology for your understanding to see when and how you can indulge on this performance enhancing food chemical. As you can see below, caffeine competes with adenosine for its receptors. This action is therefore one of the reasons why caffeine exerts its effects. However, this chemical does not behave equally for all people. This is because of the version of the gene (CYP1A2) one has, whose product is an enzyme that metabolizes it. This gene has 2 versions known as A and C. A person with AA are fast metabolizers whilst AC and CC are slow metabolizers. According to this study, AA genotypes interestingly tends to reap the performance benefits the most. If you are one of them, you should consume it 1hr prior to starting you study sessions preferrably in your biological peak performance period in the day. And if you are to drink coffee know that the concentration of caffeine may vary, although one generally gets the higher concentrations from cold brew versions. Foods that boost learning: theacrine Theacrine is an extract from bitter tea (苦茶) that one can commonly find in traditional Chinese medicine shops. This chemical comes from and is synergistic with caffeine. Since this molecule is very similar to caffeine, it also competes for the same receptor as above. However, due to the slightly different structure of this molecule, it does not result in post-caffeine jitters that slow metabolizers experience. As such this may make simultaneous use of caffeine more efficacious. Foods that boost learning: tumeric and cocoa One of the most important neuro boosters is a protein; Brain-derived neurotrophic factor BDNF. Scientists say that this compound contributes to memory development and learning which is particularly pertinent for students. As such, the hunt began to find what food induces BDNF production. 2 of them have been worked on in animals to show the increase in the neuro booster levels in the blood. These are tumeric and cocoa. My suggestion is to sprinkle tumeric powder into salads and cocoa into the hot coffee/bitter tea you are drinking (without adding sugar!). Non-foods that boost learning: nootropics The list above are easily avaliable on the supermarket isles as well as safe for consumption generally. However, depending on the genetics of the person or concentration of the beneficial chemicals, they may or may not derive any boost in learning. On the other hand, it may take some time before one experiences the positive effects. As such, a small handful of more adventurous students have gone further than food in seeking chemicals that boost learning and exam preparations instead. Many refer to these chemicals as nootropics or smart drugs. These are often only avaliable with a prescription and are synthetic. However, I do not encourage exploration in this area. Since one cannot easily reverse the consumption of these chemicals which may have adverse effects. Worse still, some of the chemicals like ritalin can be addictive! Also, since many doctors are cautious and will not prescribe these drugs some turn to online pharmacies. Since these manufacturing outfits are not regulated, one cannot trust the quality and quantity promises as well as whether they will contain impurities that may even be poisonous! In addition, students who seek these out do not usually come under medical supervision and consequently may not be sensitive enough to know when things are going side ways. So as promising as they sound, I think it is not worth the effort and the risk to indulge in nootropics. Bottom-line Whilst the foods above can be eaten or drunk to boost learning and exam preparations. Its most important not to overdose. Too much of anything is never a goood thing. For example, if caffeine is drunk round the clock, the drinker will build resistance to the chemical requiring larger doses as the adenosine receptors down regulate in response. The same chemical can also affect sleep. And I talk about the importance of sleep to learning in the past. Finally, let me know if this has been useful.

More from byang

How to find motivation during exam preparation Many students quickly lose steam during exam preparations. I am going to suggest a way to very quickly help you find motivation during exam preparation in such trying circumstances. Why you need to find motivation during exam preparation In my years of teaching, I have seen many students start out strong but quickly fizzle out in the journey to big exams. Not only do they lose appetite for the final preparations, worse still they begin forgetting concepts. This then creates a snowball effect. Where he/she sees that they are not ready for the exams and as a result begin telling themselves negative things. Which in turn further aggravates the preparations until finally, they give up altogether. Students who are suffering in this manner need to quickly get out of the funk in order to get on with the exam preparations. So that they can go on to achieve the grades they want on the graduation transcript. Which in turn open doors either to university admissions or for them to proceed on to the next stage of their life certification in hand. And I am writing this to help you find motivation during exam preparation. Ask yourself WHY?! Ironically, and most importantly the first step to beating self defeat and find motivation during exam preparation is to ask the question WHY? Why are you doing what you are doing now. A lot of students do not start out defining their reasons, instead, they plod through the motion of education. Frequently, the students are not able to muster much if any enthusiasm for life. Worse still, there’s nothing they can look forward to after graduation. Conversely, defining the reasons why you are doing what you are doing helps you to generate the motivation to tide through the pain you are suffering right this moment. It makes the journey through the exams a little better. As a result, that will start a positive feedback loop beating out the downward spiral. However, you will need guidance to properly define your reasons of why you are doing what you are doing. 7 questions of WHY, to find motivation during exam preparation It’s very easy to come up with a politically correct answer for yourself. In addition, your first answer is one that is usually a reflection of the other people’s reasons. This reason may be real but will not generate the motivation you need to push through the difficult period. Because this does not come from a place of desperation since you do not personally identify from it. Let me explain my with example. In friends ask me right now why I am doing what I am doing providing H2 Biology tuition. My standard answer will be that I have seen students suffer in school with lousy instructions in school. Therefore I want to help my students gain subject mastery and lift them out of their misery and find some direction in life. It sounds great right? And this is something I truly believe in as well since I have been doing this since 2004. However, this is not intrinsically motivating to me. This is because the students are in their moment of desperation trying to get through exams. Not me. As such, you have got to continue the line of asking why after the first reason. Like in my circumstance, ‘why do you want to help your students gain subject mastery and …’ Usually by the 5th time of the question, the answer becomes more and more desperate as you dribble down 2 times more. By the 7th WHY question, you will have found your reason and true motivation. Remember the story of a desperate mother successfully lifting a 1400kg car to free her pinned child? Desperation can create immense strength and motivation. Precisely the solution to blast you off to the moon during exam preparations. Let me tell you my reason. My true reason for doing what I am doing Back when I am teaching in school, I hit a ceiling in my teaching career. Even though I have made tremendous strides, I was refused promotion because it was not my time yet. Why did I want to keep pushing on even as a young person who has just started his teaching career? I remember even to this day an event when I was primary 1 that is permanently etched in my mind. It was a huge quarrel between my parents. My father who visits us from time to time alternating between his 2 families decided he had enough and he decided to go back to the other family. (Yes, I grew up knowing that I was a bastard) That’s not before my mum who packed up her bags screaming that she is going to leave first. I was tugging and pulling both of them at their legs. At that moment, what I felt was extreme fear. What am I going to do, all alone, no support, no money, no NOTHING. Zilch. From that moment on, I learnt I need to become self independent. I need to be on top of my game and become resource rich. With that mentality, I left the cushy school teacher job, joined startups to gain the skillset needed to open my own business and finally be in the position where I can help my students gain subject mastery and direction in life by offering H2 Biology tuition. Every time, I lack motivation, I relive the frightening event and am quivering a little as I write this. What if you cannot find that reason? In the past when I do the exercise with my students, some say that they cannot find such a reason. Such are the times of prosperity that we live in! Then let me help you create one. The next time you go to the toilet to take a dump, I want you to imagine the toilet handle is gone. Instead, you have a weak shower head to flush off the pile of foul smelling shit in the toilet bowl. Unfortunately, you cannot leave until you have sorted out and someone is knocking on the door urgently wanting in so that they can take a dump. How do you feel? Anxious? Extreme embarrassment? Wishing you were not there? Praying that you were dreaming? What if this is something that you have to content with for life? Do this for real and you have a strong reason to help find motivation during exam preparation! Find motivation during exam preparation – bottomline I know you are not going to unsee the picture above. But still, the dramatic effect is pertinent to bring my point across and to help you quickly find motivation during exam preparation. This is because time is running out and you need to have every minute ahead of you used productively. I wish you every success in your upcoming exams and you can check out other tips in the section below.
COVID-19 basics for the H2 Biology student Coronavirus whose origins in the city of Wuhan, Hubei province of China is now COVID-19. This virus have quite the profile that spread mass panic all over the world in a very short time. As such, I hope to educate all on the COVID-19 basics so that all my students can see how it relates to their syllabus. More importantly gain knowledge of this virus so as to make sense of the a barrage of news articles and different fallacies from fact. COVID-19 basics: What is it? This is the viral disease that is a result of infection with the novel coronavirus originating from Wuhan. Some scientists are also referring to the same virus as 2019-nCoV or SARS-CoV-2. The virus belongs to the family of viruses which we refer to as Coronaviridae. This virus, like all other viruses contradict the cell theory, which is also why the viral name do not follow the standard binomial naming conventions. Generally, viruses falling into this family have an envelope as well as a positive sense, ssRNA genome. Let me explain the structures and in addition, show you how they look like under the electron microscope. The envelope is the membrane that originates from the host as new virus particles buds out of the host in a bid to release themselves to infect other hosts. They do so because they cannot replicate independently and require the host cell’s replicative machinery. And this method of reproduction is also why disease arise. This is because the target cells of the the novel coronavirus are respiratory cells. Consequently the host respiratory cells can be overcome by virus reproduction resulting in the death of the cells. Remember, these cells play an important role in respiration. Consequently the lost of which would mean they cannot breath properly. Severe lost of the function can then lead to death. Let’s go on to talk about the genome so that we can begin to understand the behavior of this virus. COVID-19 basics: Genome behavior We describe the genome of the virus as positive sense, ssRNA. This means that the genetic material this virus carries is single strand RNA, which is a template for conversion to viral proteins directly. In contrast, the negative sense means that the RNA have to first undergo an additional step of conversion before the RNA can be a template to convert to viral proteins. Unfortunately, this has significant implications when it comes to the potential severity of COVID-19, as we discuss the COVID-19 basics. Firstly, this may explain the speed at which the virus spreads since the synthesis of viral proteins is much faster even though there is no signs of infection yet. Secondly, all RNA viruses have a viral gene that codes for an enzyme RNA-dependent RNA polymerase. This is because that is one enzyme the host do not have since the host do not depend on RNA as genetic material (hosts use DNA instead). The problem with the viral RNA-dependent RNA polymerase is that is lacks the ability to do proof reading. Proof-reading is the mechanism that corrects any errors arising from the replication of genetic material. Errors gives rise to mutations. This ensures a low incidence of mutations that can potentially arise from replication in humans. Increases in mutation results in cancer and other genetic diseases. Consequently this will mean that the novel coronavirus has the ability to change over time leading to a slightly different version of viral proteins. Scientists call this antigenic drift. COVID-19 basics: antigenic drift and human immunology Immunology is the study of an immune response against foreign bodies. In this case, the human immune response can eliminate the novel coronavirus by recognizing specific structures on the virus envelope. This is because viruses have specific structures on them that makes them unique much like we and our fingerprints. The problem arises due to antigenic drift. If the virus changes the specific structures on their envelope, the immune response may not kick in or be less effective recognizing the viruses. In order for them to regain the recognition, the cells of the immune response (specifically T and B cells), has to take time to learn. Since the viral replication continues unabated, it can overwhelm the host before we can fight back by producing the new version of the immune response to the new version of the novel coronavirus. This may likely be the reason why it seems that Wuhan, Hubei has such severe cases not seen elsewhere in the world. At the time of writing, there are only 1 death outside of China (not including 1 death in Hong Kong). The viruses there have undergone antigenic drift. The 1st version of the viruses is the one that the is being spread outside of China. And many are worried the moment antigenic drift occurs that can potentially lead to a wave of deaths we see in China. COVID-19 basics: how do we compare this to Influenza virus Even though there is similar behaviors between the novel coronavirus and Influenza virus, these are 2 very different viruses. Influenza virus has segmented, negative sense, ssRNA genomes. They belong to another family of viruses known as Orthomyxoviridae. It is because they infect the same target host cells and are spread in the same way that’s why it leads to confusion about these viruses. However, there are some differences in the disease though the discussion will be outside the scope here. Influenza viruses too have in the past led to devastating pandemics the last of which was around 1918 killing tens of millions of people. This has been repeating every 100 years and many are wondering if this time the novel coronavirus is it. Influenza virus genome in contrast have segmentation meaning their genes are on 8 different pieces of ssRNA. This unique feature means that if 2 different strains of virus co-infects a human then they can produce a new hybrid of the 2 virus (a swine and a human virus for example). This new hybrid virus may be so different the immune system completely loses the ability to detect and eradicate it leading to disease and spread. Scientist refer to the phenomenon as antigenic shift. In theory this makes Influenza viruses an even more potent pathogen. But it is also a sobering fact that we are living in a time where we have to monitor the ever evolving and increasing number of viral threats. COVID-19 basics: how it spreads Since we have an immediate threat of the novel coronavirus I will focus on the discussion of this virus instead. The respiratory virus can jump from one host to the next easily. This can be via direct contact transmission of which there are 3 ways. Direct (touch, kissing), indirect (touching fomites containing the virus) and droplet (result of talking, sneezing, coughing). At the moment we do not know much about this virus and some scientists suggest there may be other ways of spreading. The discussion of them is outside the scope of this article. As such if one practices personal hygiene and employing protective measures they may reduce chances of becoming infected. The natural next question is why don’t we know about this virus? novel coronavirus The most straight forward answer is that these viruses do not originate from nor use humans as host. Recently, China scientists who have samples of the virus have subject it to phylogenetic analysis revealing that it may have come from Pangolins. Please note, I cannot confirm the validity of this observation as no other scientist outside of China currently have access to the data to confirm this. If true, this differs from the SARS virus which is another related virus from the same family originating from bats. It is likely however that the passing of these viruses from the original animals is due to the close human contact. Which in this case is the hunting, trading as well as slaughtering of this animals for eventual consumption. By chance, this interaction is successful allowing the virus to replicate. As they do so, antigenic drift may occur allowing new viruses to be even more successful at infecting humans. This follows natural selection where the more successful progeny viruses are advantaged since as they increase in numbers faster than those other viruses that have not undergone the same antigenic drift. Consequently, this leads to human to human transmission which we are currently observing. Bottom-line I hope you have a much better idea of COVID-19 basics and the many areas that relate to H2 biology syllabus. Although we are experiencing this epidemic in Singapore, my hope is that it can be curtailed so that our lives can return back to normal finally. Do you have any questions pertaining to this virus? If so, let me know!
Foods that boost learning or exam preparations Many students focus on cramming content in the hopes of boosting their scores for assessments without realising that they can get a bit of help from foods that boost learning or exam preparations. Why use foods that boost learning or exam preparations You are already eating everyday, why not fine tune what you consume with foods that boost learning or exam preparations in order to get yourself that bit of edge versus your compatriots? This can also be in addition to many of these foods having other positive effects on the body. Foods I am going to list contains certain chemicals, which correlates with increase in cognitive performance. Since these are natural components of food, it has little side effects and are also affordable. However, please consult your doctor or dietitian especially to determine if you have any allergies before incorporating any of them. Foods that boost learning: caffeine Caffeine is one of the most important chemicals in foods that boost learning by increasing cognitive and physical performance. Drinks rich in caffeine such as coffee is not surprisingly most commonly drunk for students seeking that increase in cognitive performance. Let me simplify the biology for your understanding to see when and how you can indulge on this performance enhancing food chemical. As you can see below, caffeine competes with adenosine for its receptors. This action is therefore one of the reasons why caffeine exerts its effects. However, this chemical does not behave equally for all people. This is because of the version of the gene (CYP1A2) one has, whose product is an enzyme that metabolizes it. This gene has 2 versions known as A and C. A person with AA are fast metabolizers whilst AC and CC are slow metabolizers. According to this study, AA genotypes interestingly tends to reap the performance benefits the most. If you are one of them, you should consume it 1hr prior to starting you study sessions preferrably in your biological peak performance period in the day. And if you are to drink coffee know that the concentration of caffeine may vary, although one generally gets the higher concentrations from cold brew versions. Foods that boost learning: theacrine Theacrine is an extract from bitter tea (苦茶) that one can commonly find in traditional Chinese medicine shops. This chemical comes from and is synergistic with caffeine. Since this molecule is very similar to caffeine, it also competes for the same receptor as above. However, due to the slightly different structure of this molecule, it does not result in post-caffeine jitters that slow metabolizers experience. As such this may make simultaneous use of caffeine more efficacious. Foods that boost learning: tumeric and cocoa One of the most important neuro boosters is a protein; Brain-derived neurotrophic factor BDNF. Scientists say that this compound contributes to memory development and learning which is particularly pertinent for students. As such, the hunt began to find what food induces BDNF production. 2 of them have been worked on in animals to show the increase in the neuro booster levels in the blood. These are tumeric and cocoa. My suggestion is to sprinkle tumeric powder into salads and cocoa into the hot coffee/bitter tea you are drinking (without adding sugar!). Non-foods that boost learning: nootropics The list above are easily avaliable on the supermarket isles as well as safe for consumption generally. However, depending on the genetics of the person or concentration of the beneficial chemicals, they may or may not derive any boost in learning. On the other hand, it may take some time before one experiences the positive effects. As such, a small handful of more adventurous students have gone further than food in seeking chemicals that boost learning and exam preparations instead. Many refer to these chemicals as nootropics or smart drugs. These are often only avaliable with a prescription and are synthetic. However, I do not encourage exploration in this area. Since one cannot easily reverse the consumption of these chemicals which may have adverse effects. Worse still, some of the chemicals like ritalin can be addictive! Also, since many doctors are cautious and will not prescribe these drugs some turn to online pharmacies. Since these manufacturing outfits are not regulated, one cannot trust the quality and quantity promises as well as whether they will contain impurities that may even be poisonous! In addition, students who seek these out do not usually come under medical supervision and consequently may not be sensitive enough to know when things are going side ways. So as promising as they sound, I think it is not worth the effort and the risk to indulge in nootropics. Bottom-line Whilst the foods above can be eaten or drunk to boost learning and exam preparations. Its most important not to overdose. Too much of anything is never a goood thing. For example, if caffeine is drunk round the clock, the drinker will build resistance to the chemical requiring larger doses as the adenosine receptors down regulate in response. The same chemical can also affect sleep. And I talk about the importance of sleep to learning in the past. Finally, let me know if this has been useful.
close
Minds LIVE EVENT in NYC on June 25.  Tickets on sale now!