Science tip: There will be a question or two about the digestive system. Here are the key points: – Digestive juices are produced in the mouth, the stomach, and the small intestine. – Mouth – main role is to chew / churn and secrete digestive juice (saliva). – Stomach – main role is to digest[…]
Science tip: Stomata allows gaseous exchange between the plant and the atmosphere. It allows in carbon dioxide and oxygen for photosynthesis and respiration respectively. Carbon dioxide produced during respiration can also escape through these pores; similarly, oxygen produced during photosynthesis also escape. Water vapour always leaves through the stomata. Usually, stomata will shut during the[…]
Science tip: The north end of magnets are so called because, freely suspended, they point towards the Earth’s North Pole. The north pole of a compass needle (usually coloured red or black) also points towards the Earth’s North Pole. Since opposite poles attract, the north pole of a compass needle is attracted to a magnet’s[…]
Science fact: Red blood cells in humans do not have a nucleus, as such they cannot carry out cell division. Red blood cells develop in bone marrow and circulate in the body for around 120 days. They contain haemoglobin which helps transport oxygen around the body. The iron in haemoglobin combines with oxygen to give[…]
Science tip: Evaporation of water absorbs heat energy from the surroundings. The full explanation is out of syllabus but for those interested, you can read up on latent heat and enthalpy of vaporization. Similarly, melting of ice also absorbs heat energy. From past year’s PSLE: Some buildings use a cooling mist system 2 lower the[…]
Science tip: Question: Is a helium or hot air balloon affected by gravitational force? Ans: Yes it is! All objects (with mass) in the Earth’s gravitational field are affected by gravity. This includes objects that are lighter than air. The reason hot air balloons float is not because they are weightless, it is because they[…]
Science tip: Many schools have workshops for parents of P5 and P6 students. Here are two presentation slides that may be useful. http://www.rivervalepri.moe.edu.sg/wbn/slot/u1724/Dept/Science/P5n6%20Science%20parents%20workshop%202%201.pdf http://www.radinmaspri.moe.edu.sg/wbn/slot/u3201/Presentations/Answering%20Science%20Process%20Skills%20Questions%20(P5%20%26%20P6).pdf
Science tip: For open ended questions, look at the first word of the question. It tells you a lot about what is the expected answer and what you need to do.
Science tip: Here’s a very interesting question. Some people answered (1), some people answered (2). Some teachers can’t explain why. The answer is (2). The reason is because we don’t know why the bulb doesn’t light up. It could be due to A. It could be due to B. It could be due to a[…]
Science tip: All objects at the same place experience a gravitational FORCE (or pull) that is proportional to its mass. So the larger the mass, the larger the gravitational force. This force is there regardless of the speed or orientation of the object. It is there whether the object is flying or falling, whether it’s[…]