Contemporary Science Issues

Many people in the world are under the threat of malaria and many scientists are trying to find ways to stop malaria. There have been multiple measures that have been meted out and some ideas that are yet to become a reality.

For example, scientists genetically modify bacteria in mosquitoes for malaria control.
http://www.infowars.com/scientists-genetically-modify-bacteria-in-mosquitoes-for-malaria-control/

There are also other methods such as


taken from BBC knowledge, Asia Edition Volume 4 Issue B

I hope that  scientists around the world can quickly solve the worlds problems as malaria is a serious problem and it kills many people around the world everyday.

Term 3 summary.

In term 3, I learned about unicellular and multi cellular organisms.. All living things are made of one or more cells. Living things with just one cell are called unicellular organisms. Examples of which are amoeba, Paramecium and yeast. Most living things are multi cellular and are bade up of more than one cell and are called multi cellular organisms.


I also learned about animal cells. Animal cells have cell membranes, vacuoles, cytoplasms, nucleus and chromosomes. Chromosomes are found in the nucleus and are made of DNA and proteins, and they contain genes which are passed down from generation to generation..

I also learnt about plant cells. Plant cells have a cellulose cell wall, a cell membrane, vacuoles, cytoplasm, nucleus and chloroplasts. Cellulose is a compound containing carbon, hydrogon and oxygen and is a type of fibre.

I also learned about the different shapes and functions of different cells like guard cells, nerve cells and red blood cells. In multicellular organisms, cells of the same type group together to perform the same job called tissues, for example nerve tissue, muscle tissue, and epithelial tissue. On the other hand, there are plant tissue such as vascular tissue, dermal tissue and ground tissue. Different tissues are usually grouped together to form an organ.

I also learned about osmosis. A water molecule is not very large. It consists of very smalls atoms. When osmosis occurs, a water molecule passes through a semi permeable membrane, leaving the water pure with other impurities left behind because they are too big to pass through the semi permeable membrane. I also learned the difference between an isotonic solution, hypotonic solution and a hypertonic solution, and the different effects of osmosis on the three solutions.


I also learned about how enzymes play a part in digestion, and the difference between chemical and physical digestion. I learned 4 different enzymes- Amylase, Maltase, Protease and Lipase. I also learned about the difference about the alimentary canal and the digestive system. I also learned the use of Pancreas juices and bile.


I also learned more about photosyntheses. Photosynthesis is the process by which plants use carbon dioxide use carbon dioxide, water and light trapped by chlorophyll to make food in the form of glucose, with oxygen given off. Photosynthesis takes place in chloroplasts and chlorophyll appears green because of green pigments in the chlorophyll. I also learned how to test for starch using iodine solution.


I also learned about respiration. There are 2 types of respiration, Aerobic and Anaerobic respiration. Aerobic respiration is the process whereby glucose is broken down in the presence of oxygen with the large release of energy in cells. Water and carbon dioxide are released as waster products.

Tissue respiration is the process where glucose is broken down in cells. A large amount of energy is released to perform different activities. Breathing is the process of bringing oxygen from the surrounding environments into the body. It also removes oxygen and carbon dioxide form the body. Most organisms respire aerobically. Energy is used for growth, muscle contractions, digestion and cell division.

The human respiratory system consists of the nose, nasal cavity, pharynx, trachea, bronchus, bronchioles, alveoli, diaphragm and lungs. Air enters and exits two external nostrils. Breathing is the physical process by which respiratory gases are exchanged with the surroundings. In inhalation/Inspiration, air is taken in from the surroundings while in exhalation/expiration, air is given out from the body. In inhaled air, there is more oxygen, less carbon dioxide and less water vapour than compared to exhaled air.


Overall, i enjoyed term 3 science as i learned a lot of new stuff about photosyntheses and respiration and osmosis. I hope that the rest of my science journey is as interesting as this years science topics.

Practicals 6-10 Measurements, Graph techniques and Kinetic particle theory.

1P6 Measurements of length
The important apparatus we used today were the metre ruler, vernier calipers, micrometer screw gauge. Today was a first of its kind lesson because we did some very interesting experiments with the various instruments of measurement. First, we used the meter rule and checked its smallest rule, and then we measured the hight of our seat from the floor at 4 different positions and took the average reading. Then, we conducted similar experiments with the vernier calipers and micrometer screw gauges. We were then tested on what we had learned with a few questions about what instruments we would use to measure something and were made to suggest a way to measure the diameter of a long piece of wire using only a metre rule and a uniform glass rod. Today was a very interesting lesson as i got a chance to try using these instruments for the first time and it felt fun measuring tiny measurements.




1P7 Determining density
Today, we measured the density of the density of a small glass marble.It was very interesting because until now, i had no idea what density was. It was interesting to use so many different ways to measure density of so many objects. First, I weighed the marbles and then found the volume of the marbles. I divided the weight by the volume to come up with the density of the marbles. The formula for determining density is mass/volume.

We also determined the density of irregular solids. First, we placed the object in a beaker of water and compared the new reading with the reading taken when the object was not in the water to determine the mass. After that, we used the formula to determine the density.


1P8 Brownian motion
Today, i learned about Brownian motion. I was very interested as it was a science theory i had never heard of before and i was curious to learn more. Brownian motion was discovered in 1827 and it proves that a gas consists of invisible molecules moving around constantly, randomly and at high speeds. Today's lesson was memorable because I learnt something that I mixed up with diffusion and it corrected my misunderstanding, clearing up two things in my mind.



















1P9 Investigating Mixtures and Compounds

Today, we investigated the properties of a mixture and a compound. We used tripod stands, evaporating dishes, glass rods, wire gauze and Bunsen burners. First, we thought about what the difference between mixtures and compounds was and how to identify them.We heated the sulphur powder and iron filings to form a black solid. We discovered that this black solid had completely different characteristics compared to the individual elements. This was because the iron and sulphur had undergone a chemical reaction that changed its atomic structure, giving it completely different characteristics.

Then, we formed certain conclusions about chemical reactions. I concluded that heat is needed to form compounds and cannot be separated by physical methods nor have the properties of its constituent elements.

Term 2 Summary.

The topics for term 2 are Measurements, Graph techniques and Kinetic Particle Theory.

The first thing i learnt this term was what Matter was and the states of Matter. I was not particularly interested in this part as many have already learnt this in primary school. Next, we learnt about the Kinetic Particle Theory. I greatly enjoyed this part of Science term 2 because this was something completely new. At first, i had trouble seeing the difference between this theory and diffusion and how they could coexist, but in the end i managed to understand it. I learnt that the Kinetic Particle Theory states that mater is made of tiny particles, which are in constant and random motion.


Next, I learned about diffusion. In diffusion, particles move randomly from a region of high concentration to a region of lower concentration.
For, example, if a bottle of perfume is opened in one corner of a room, we can smell it in another corner after a very short time. Thus, diffusion can be proven. Bromine vapour can be used to show the diffusion of gases, Because it is brown in colour. Using this, we can see the vapour diffusion throughout the room.

I also learned about the molecular model of the three states of matter. I felt bored about this section because I had already learned this. I also learned about the changes of state in matter. That included melting, freezing and boiling. Once again, i had already learnt this.

I also learned about Elements, Compounds and mixtures. Elements are substances that cannot be broken down into simpler substances by any known chemical methods. Scientists have classified elements into a chart called he periodic table. The have columns called groups and rows called periods. Elements are grouped according to their properties. Each element is represented by a unique symbol and each element is given a number called the atomic number.

Atoms are the smallest particle of any element. Each element consists of a particular type of atoms. two or more atoms held together by chemical bonds are called molecules.In a physical change, no new substance is formed. But in a chemical change, a new substance is formed. Compounds are a substance containing two or more elements joined together by a chemical reaction. A compound has very different properties from its elements. However, in mixtures, the atoms of the elements are not chemically, combined. 

I also learned about solutions and suspensions. Solutions are mixtures that consists of a solvent and a solute. Solutions are homogeneous when the colour and density, appearance and other physical and chemical properties are the same in every part of the solution. The solubility of a substance in  a solvent is the maximum quantity of that substance which can dissolve in 100g of the solvent at a given temperature. (Units: g/100)
Suspensions are formed when the substance does not dissolve in the solvent or when the amount of substance present is over its solubility limit. Suspensions are cloudy and non-homogeneous.
 
I also learned about separation techniques, such as filtration, crystallisation, the difference between crystallisation and evaporation to dryness, magnetic attraction, distillation, fractional distillation, separating funnel and paper chromatography.

Overall, i greatly enjoyed term 2 science because I learnt what from young I had thought was chemistry was. I dealt with chemical reactions and separation techniques which were very interesting and fun, as i had never seen anything like it.

Practicals 1-5 Introduction to Science and the Scientific method.

1P1 Getting to know the Science Laboratory

Today, we learned about the layout of the science lab and the various thing in a Science lab. We learned where all the important features such as first aid boxes, gas taps, power points and fire extinguishers were located in case we needed to use them.We also learned about the standard hazard symbols used to denote explosives, flammable materials, toxic materials, corrosive materials and radioactive materials.

                                     

We also learned how to draw the various instrument used in lab experiments and we took note on how to draw the various equipment such as Bunsen burners, test-tubes and beakers. We also learned about what they were used for and how we should use them. I felt excited as it was my first lab lessons and I greatly enjoyed it.

1P2 Hot stuff with flames

Today, we learned the anatomy of a Bunsen Burner.

There is the barrel, collar, gas tap, air hole, gas jet and base.

We also learned how to light the Bunsen Burner and the possibilities of a strike back.

Then, we learned about the difference between a non luminous flame and a luminous flame. A luminous flame is not as hot as a non luminous flame and only the non luminous flame should be used for heating objects.

Then we carried out our first experiment. We heated a test-tube of water until it boiled and then placed it in a test-tube rack to cool. It was interesting to use the Bunsen burner for the first time.

1P3 Observing and Recording part 1

Today, we did a series of experiments that tested our ability to make observations. The experiments involved dissolving  copper sulfate,  methylated spirits. It was interesting to experiment using many different elements and it was rather exciting to see the result of the experiments. After that, we drew a "space creature" from observations given to us. It was an interesting experience using our imagination creating something that existed within the parameters of a few lines of text.

1P4 Observing and Recording part 2

Today was a very fun lab lesson. We heated a beaker of water using a Bunsen burner and measured the temperature with a thermometer. Then, we recorded the data to plot a line graph. However, i plotted the line graph wrongly, with mistakes like incorrect labelling of data points and drawing multiple lines for the curve.  I hope that i can learn from my mistake and correctly label my graphs so as to prevent losing marks from careless mistakes in the future.

Term 1 Summary

The topic learned in term 1 is Science introduction to Science and the Scientific method.

I learned about the three major elements of science which are attitudes, processes and methods and products. We must have the proper attitudes for learning, the proper process skills to conduct experiments and contribute to Science in order to learn Science. I also learned about the benefits of Science and technology and the abuses of Science technology. I makes me  happy to see the way Science has benefited the world as a whole but in some ways it has harmed the world, peoples and animals alike. We all share this world together and cannot afford to waste resources for convenience and cause pain and suffering to others who share our planet. I also read about the limitations of science. i learned that there are indeed limits that we cannot cross such as seeing the future and time travel, although one day, we might be able to do so.

I also learned about the lab rules and lab protocol. I learned how to react if anything should happen and how to fix any problems. These rules are important because if they are not followed people can get hurt in ways and places more than one.

I also earned about drawing scientist's tools and their purposes. For example,  a fla-bottomed flask is used to contain chemicals when preparing bases if the process requires no heating while the beaker is used to contain chemicals or liquids.

I also learned about Bunsen burners. i learned the difference between luminous flames and non luminous flames and tried them out using the Bunsen burner itself. We learned about the dangers of a strike back and how to heat a liquid in a test-tube. We also learned about the Scientific method and how we can use the individual skills required.

I also learned about the metre rule, parallax error and the various instruments of measurement, such as vernier calipers, micrometer screw gauges and rulers and how to use them. I also learned how to measure area and volume, using instruments like burettes, pipettes and measuring flasks.I learned about concave meniscus and convex meniscus, and most importantly, time measurements.

I also learned about some "special names" for physical quantities, for example newton and volt. It was interesting to learn about these terms and how physical quantities can be defined as. Another thing i learned was the importance of units. I learned terms like base quantity and base unit and formulas to calculate certain things. I learned the difference between mass and weight and the different measuring devices. 

Overall, i greatly enjoyed term 1's science lessons as they were very new to me and allowed me to understand what secondary school science was all about. It showed me how to use a laboratory and lots of different equipment.

Here are some of my personal ACE work samples:

And