Learning Issues and Lab Lessons

Term 1:
Topics- Atomic Structure, Chemical Bonding, Acid & Alkali, Period Table

Being a person who rarely excel in Science and getting merely borderline grades due to the fact that Science was one of my weaker subjects ever since primary school. Nevertheless, I struggled with the daily assignments given by Ms Nada on the respective topics, specifically on equation writing. I personally did some independent learning online by watching ‘YouTube’ videos on how to write equations. However, I was still confused and consulted my siblings and friends instead. Fortunately, they aided me along by asking me to firstly to memorise the different structures of the elements and that helped me tremendously.

Lab lessons were also beneficial. Unlike other teachers, our teacher, Ms Nada, allowed us to do the experiments on ourselves first and there was not a need to have a demonstration. From the very first lesson, we could see that she is very strict and concerned of the safety and behavior we have in the laboratory as accidents can occur very easily if we are fooling around or not alert. This term we experimented on acid and alkalis and also got a special opportunity to mix with chemicals. These lab lessons were important to me as they help me remember key concepts better such as red litmus will turn blue when in contact of acid.

Term 2:
Topics- Cycles, Sexual Reproduction

Even though the topics covered in term 2 though it seemed quite little, there were still many stuff to remember as Sexual reproduction branches out to many different topics such as menstrual cycle, STDs etc. Furthermore, acids and alkali is a very broad topic, thus we crammed all these information in order to be prepared for the tests. In my opinion the hardest were to remember the formulas for the common ionic compounds to be applied during equation writing. Unfortunately, there were no lab lessons in this term as it was mostly focused on sexual reproduction.

Term 3:
Topics- Light, Ecology

In term 3 we focused on Light and Ecology. Ecology was much simple and easier to understand when taught as food web and food chain have already been covered in primary school, so we had some basics at hand. However, the tough part for Ecology is to explain the abiotic factors and how it affects the environment. On the other hand, Light was much more challenging as we are also required to draw ray diagrams. A single mistake like drawing arrows wrongly to indicate the path/direction of light could cost you the entire question. But after much practice using the "shortcut" method, everything seemed easier.

Lab lessons this term were also enriching even though i missed some due to involvement in competitions. Unlike term 1, this term we did not work with chemicals, instead we worked with mirrors and light rays. We had the opportunity to witness how light reflects when come into contact of different shapes and mirrors. My favourite experiment was the one where we get to see total internal reflection. These experiments really aided me in memorising concepts, and to visualise to be able to draw the ray diagram.

HBL 24/5/11

In Term 2 Week 10, we had our Home-based learning. For science, we covered on Ecology, about the different relationships between organisms in an Eco-system. In short, this Home-based learning was fun, interesting and at the same time, useful.

Even though Ms Nada have briefly gone through these key concepts in class (such as predation, mutualism etc.), I am still not very good in working with these articles and identifying the respective relationships. Therefore, this Home-based learning was a great chance for me to really get hold of the basic concepts and also acts like a recap for the upcoming tests. Furthermore, I also had a better understanding and can now give examples of the types of relationships as in this activity we were told to describe the relationship of other creatures.

Personally, I actually enjoyed this home-based learning the most, as it was impactful and yet I am able to complete it in the short 1 hour period and do not have to spend quite some time like other subjects. I feel that having more of these kind of home-based learning is really good, and can really aid us in our understanding better.

Answers:

Q2. Since the Amazonian trees ants live only in the Hirtella physophora and the Amazon regions faces deforestation, deforestation will cause a decrease in the number of Hirtella physophora. This will also cause a gradual decrease in these ants as there would be more difficulty in finding places where they can inhibit and also decreasing the number of resources to build their traps, to capture their prey.

Q3(a).

Mutualism : The relationship between the ants and the plant host.

The plant provides ant with shelter and resources to construct the trap while the ants protect the plant host using their traps to protect the plant against parasitic insects and plants.

Commensalism : The relationship between the ants and the mould.

The ant makes holes in the platform and put in places pieces of sooty mould, which would quickly grow around the structure and reinforce it. On the other hand, the mould get nothing in return.

Predation : The relationship between the ants and their prey.

The ant prey on their insect and kills them. With one side benefiting, the other party suffer.

Q3.(b)

Mutualism : Clownfish and sea anemone.
The examples of mutualism include the sea anemones and hermit crab. The sea anemones give protection to the crab using its stinging cells, and it remoulds its shell to fit the crab while the hermit crab allows the sea anemones to consume the remains of its food, thus it also provides the sea anemones with food supply, which makes it a relationship beneficial to both.

Commensalism : Tree frog and plants living on trees

The tree frog uses the plants on trees for protection from the rain, and the plants are not affected at all.

Predation : Lion and deer
The lion eating the deer.

Water Shortage

Article :

There are already around 3 billion people in the world struggling to keep up with the demand for the fresh water. This number is expected to double in the next 20 years and there has been several different possible solutions for this issue such as conservation and reuse but one of the most interesting solutions definitely looks to be desalination. Why desalination? Well, lets just say that our oceans cover around 70% of our planet and therefore represent the virtually inexhaustible source of water. So why not use water desalination then and fix the water shortage problem? The main problem with desalination is that the process of removing salt from the seawater is extremely energy intensive and therefore highly expensive. There have been many different scientific studies which tried to make desalination process commercially viable but none of it has so far managed in achieving this. The currently dominating process of desalination is the so called reversal osmosis in which seawater is forced through a membrane that filters out the salt. The scientists have done several studies in which they tried to increases the membrane's water flux, and the latest researches which used carbon nanotubes have proved to be the most promising of them all. One of the most interesting recent studies comes from the University of Notre Dame. According to this study it is pointless to try to increase the membrane's water flux because the current technology is already starting to approach its efficiency limit and science should instead focus on possible gains in efficiency during the pre- and post-treatment stages of desalination. The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected.

Thoughts:

In Singapore, we have the four national taps which apart from desalination, consists of imported water, water from catchment areas and NEWater. Currently, Singapore has a desalination plant in Tuas built in 2005. Even though desalination takes up only about 10% of Singapore's water supply, in the future it is going to be a key pillar of Singapore's sustainable water supply along with NEWater which contributes 30% of consumable water. The other sources of obtaining water such as imported water are not long term solutions as agreements will expire and whether the country plans to continue the agreement with Singapore is up to the other party and this could make Singapore vulnerable even though imported water is the most efficient way and it also does not use much land space. Furthermore, despite being able to keep the cost of water treatment down, this is not a great solution too. Singapore currently has 15 reservoirs and to collect more rainwater more catchment ares have to be build and this is not very feasible as Singapore is faced with land constraints and currently, the area of the catchment areas covers up to half of Singapore's land. Therefore, i agree with the article where it claims that " The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected. " This is very likely as we a quite a rich nation, thus we can afford such technologies and the abundance of sea water available.

Reflection (Term 3)

In a blink of an eye, we have come to the end of a hectic term 3. This term was filled with competitions which resulted in missing certain lessons, thus having to catch up each time. This term's topic was on light. Practical lessons were down to the minimum considering the lack of time as method of learning was different from the previous terms. This term it was more of independence in self-study learning in which lessons were only used to clarify doubts and going through of answers in our worksheets.

Unfortunately for me, i faced difficulty trying to understand the topic depending solely on myself. I always get puzzled by the difference between convex and concave mirror, and how the image will appear on both mirrors. The drawing of the ray diagrams was also a huge hurdle for me. However, the problem was easily solved when i went to seek help from my willing friends and also my elder sister.

As physics is not a subject that could be memorised, we still hid a few scarce practical lessons to have hands-on session. This aided me a lot in understanding the laws of physics and light, both reflection and refraction.

For this term’s test, even though I got 33/40 which is an A1, I am still very much disappointed in my results as I was far below average and at least 4 marks were lost due to carelessness and sloppy drawing. To make matters worse, the test was also rather easy with only a handful that did not get A1. Now that I have basically no chance of an exemption, I will have to start on my revision for the EOYs soon, aiming for yet another A1.

Marine Biodiversity

Marine Biodiversity

Definition

- ‘Biodiversity’ is commonly defined as the variety of life in genes, species and habitats.

- For instance, the species that inhabit Singapore are different from those in Thailand, the plants and animals have different characteristics and needs, even though some of the same species can be found in all of those areas.

Importance of Biodiversity

-All living organisms are part of the web of life. Each species of vegetation and each creature has a place on the earth and plays a vital role in the circle of life.

-Biodiversity performs economic, aesthetic and recreational value

-At least 40 per cent of the world’s economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change.

Threats

The living inhabitants of the marine realm face four major threats:

-Overfishing (most harmful)

-Habitat damage

-Climate change

-Pollution

Overfishing

-Fishing is central to the livelihood and food security of 200 million people, especially in the developing world

-One of five people on this planet depends on fish as the primary source of protein.

-From commercial fishing, recreational fishing, illegal unregulated or unreported fishing.

-Fishing is identified as the main threat to marine ecosystems. According to a Food and Agriculture Organization (FAO) estimate, over 70% of the world’s fish species are either fully exploited or depleted.

Habit Damage

-Fishing gear commonly used to catch shrimp and bottom fish like cod and haddock, can cause long-term damage to sensitive marine ecosystems.

-E.g. A damaging method known as dredging pulls nets with a chain mesh base through soft sand or mud to catch scallops and sea urchins. These fishing gears severely destroy the ocean floor and damage the places where fish feed and breed.

Climate Change

-Human induced climate change - affects ocean temperature and levels.

-The marine creatures have to constantly adapt to the changed environment and subsequently, some eventually dying because of the drastic change.

-E.g. The increase in temperature level will cause the ice to melt, which may destroy the polar bear’s habitat

Pollution

-Most if not all pollution (air, land and many more) ultimately enters the sea.

-Marine biodiversity is thus most exposed to and critically influences the fate of pollutants in the world.

- Yet marine species are probably least resistant to toxicants. The spread of pollutants in marine food chains and therefore the quality of marine food is uncontrollable by humans.

Marvin Gaye - Mercy, Mercy Me (The Ecology)

Lyrics :

Woo ah, mercy mercy me
Ah things ain't what they used to be, no no
Where did all the blue skies go?
Poison is the wind that blows from the north and south and east
Woo mercy, mercy me, mercy father
Ah things ain't what they used to be, no no
Oil wasted on the ocean and upon our seas, fish full of mercury
Ah oh mercy, mercy me
Ah things ain't what they used to be, no no
Radiation under ground and in the sky
Animals and birds who live nearby are dying
Oh mercy, mercy me
Ah things ain't what they used to be
What about this overcrowded land
How much more abuse from man can she stand?
Oh, na na...
My sweet Lord... No
My Lord... My sweet Lord

Recently i happen to come across this song while researching stuffs on ecology. I feel that this song is really meaningful through using music to tell people about how fast the biodiversity is disappearing through pollution etc.

This is the video on youtube :

http://www.youtube.com/watch?v=U9BA6fFGMjI&feature=related

Lightning (ACE)

This is my ACE video on Lightning :

Enjoy! :)

Lightning - Jovian Tan 2A2(31)
by: Jovian Tan