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Biology Tuition Singapore Secondary Science Tuition – Cells Questions   Q1) Which of the following is not found in a typical animal cell? A. Cell membrane B. Nucleus C. Vacuole D. Cell wall   Q2) Which of the following statements is true? A. A cell is the basic unit for animals only. B. A multicellular organism has more than one cell in its body. C. Plant cells and animal cells only differ in terms of cell wall. D. A unicellular organism does not need a nucleus to function.   Q3) Which of the following characteristics is true for cell wall? A. They restrict the movement of substances across the cell. B. They support the cellular structure in animal cells from bursting when water enters the cell excessively. C. They are made up of cellulose that cannot be digested by an ...

Physics Tuition Singapore Secondary Science Tuition – Electricity Chemical Effect   Chemical effect A chemical change caused by electricity is called electrolysis An electrolyte is a liquid or a solution which can conduct electricity. The electrolyte undergoes chemical change when electricity passes through it. Electrodes are electrical contacts which allows electric current to leave and to enter the electrolyte. Electrolysis is widely used in electroplating and in the extraction of metals. Electroplating In electroplating, an object is coated with a layer of metal. The object to be coated is connected to the negative terminal of the power supply. The metal to coat an object is connected to the positive terminal of the power supply. The purpose for electroplating an object: For ...

Chemistry Tuition Singapore Secondary Science Tuition – Atoms. Ions and Molecules   IONS All atoms are electrically neutral. They have equal number of protons and electrons. When an atom loses or gains electrons, the number of protons is not equal to the number of electrons Therefore, the atom will not be electrically neutral. When an atom is not electrically neutral, it is called an   There are two types of ions: If an atom loses electron(s), it becomes a positive ion.  If an atom gains electron(s), it becomes a negative ion In the formation of ions, the process only involves the gaining or losing Therefore, electrons are responsible for chemical properties of an atom. The number of protons and neutrons remains the same. Therefore, proton number and mass number are not aff ...

Biology Tuition Singapore A Level H2 H1 Biology Tuition – ISOLATION CLONING SEQUENCING DNA-Preparation of Genomic DNA   Assume that you are trying to insert a gene into a plasmid. Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be A insert the fragments cut with X directly into the plasmid without cutting the plasmid B cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid C cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme D cut the plasmid twice with restriction enzy ...

Economics Tuition Singapore A Level H2 H1 Economics Tuition – Fears are growing that the UK   Fears are growing that the UK is running the risk of a period of painful “stagflation” – the toxic cocktail of stagnating growth, high unemployment and rising prices Discuss whether the Singapore government should focus more on achieving low unemployment or price stability.   Introduction  Every government has four macroeconomic objectives that it seeks to achieve, i.e. sustained economic growth, low unemployment, low inflation and a healthy balance of payments. Clarify key terms: Price stability Low unemployment  Body  Singapore government should focus more on achieving price stability compared to low unemployment rate. External Benefit – Improvement in balance of payments       P ...