Download HighFour General Sciences Round 2 Category A: Grades 4 – 5

HighFour General Sciences Category A: Grades 4 – 5 Round 2 Monday, October 17, 2016 The use of calculator is not required. Answer #1 Explanation: Answer #2 Explanation: Answer #3 Explanation: Answer #4 Explanation: B Gas expands the most when heated as compared to solids and liquids. Since nitrogen is a gas, it will expand the most when heat is applied. D The plastic box is the only material that is a poor conductor of heat. Hence, it will not be able to conduct heat well. The other three materials are metals and they are good conductors of heat. D When the lid is placed in the basin of hot water, it will heat up and expand. When the bottom of the jar comes into contact with some ice, it will cool down and contract. The lid, now slightly loosened, will then be easy to remove from the jar. A Magnetism can pass through non-­‐magnetic materials, such as glass, wood, or plastic. A magnet does not become stronger when it attracts more iron nails. Magnets can only attract iron, steel, nickel and cobalt, but not other metals. A magnet can act from all its parts but the poles have the strongest pulls. HighFour General Sciences Category A: Grades 4 – 5 Round 2 Monday, October 17, 2016 The use of calculator is not required. Answer #5 Explanation: Answer #6 Explanation: Answer #7 Explanation: Answer #8 Explanation: C Magnetism can pass through oil as it is a non-­‐magnetic material. Heating it, dropping it and hitting it repeatedly will cause it to lose its magnetism. C Rubbing a stone on the ground, sawing a piece of wood, and leaving the radio on will produce heat. Leaving a cup of tea in the fridge will only cause it to lose heat. D Chlorophyll is the green pigment found in the leaves of a plant that helps it to trap sunlight. C Both ferns and fungi reproduce from spores. HighFour General Sciences Category A: Grades 4 – 5 Round 2 Monday, October 17, 2016 The use of calculator is not required. Answer #9 Explanation: Answer #10 Explanation: Answer #11 Explanation: Answer #12 Explanation: A The length of the large intestine is shorter than the small intestine by 1.5 meters. Food stays in our stomach for 2-­‐3 hours. Waste leaves our body through the anus. The rectum is where wastes are temporarily stored before it is passed out of the body. The digestive juice from saliva is the first to act on the food we consume. D The stem of a plant helps to transport food made by the leaves, and water and mineral salts absorbed by the roots to all parts of the plants. It also supports the branches and leaves so that the plant can get sufficient amount of sunlight. The stem does not carry carbon dioxide to all parts of the plant. Carbon dioxide is taken in by the leaves during photosynthesis. Once the food is made, it is transported to all parts of the plant. A Maglev systems do not use steel wheels on steel rails. Because magnetic levitation trains do not touch the guide way the high cost of maintaining precise alignment of the tracks to avoid excessive vibration and rail deterioration at high speeds is not a problem. This confers advantages such as: faster acceleration and braking, and greater climbing capability. B The spider has eight legs and therefore, it cannot be classified as an insect. It is an arachnid. Arachnids belong to an even larger group of animals called “arthropods” which also include insects and crustaceans (lobster, crabs, shrimp, and barnacles). This is the largest group in the animal kingdom. Approximately 80% of all animals are from this group, that would be over a million different species. HighFour General Sciences Category A: Grades 4 – 5 Round 2 Monday, October 17, 2016 The use of calculator is not required. Answer #13 Explanation: Answer#14 Explanation: Answer #15 Explanation: Answer #16 Explanation: B Cotton comes from the fruit of the cotton plants. Silk is from the cocoons of the silkworms. Nylon is obtained from chemicals extracted from petroleum. Wool is the fur of some mammals like the sheep and goat. BD There is reduced air pressure and lower oxygen concentration at high altitudes. Fluid may collect in the lungs. This causes shortness of breath. It also reduces the amount of oxygen entering the bloodstream to reach the cells in our body. B Our teeth help us to bite our food into smaller sizes as we cannot swallow everything whole. We then chew to even smaller pieces to be mixed with saliva for easier swallowing. Babies and some elderly people need food that is mashed before they eat as they do not have teeth to help them grind the food into smaller pieces. AC Heating the magnet over a flame or dropping it repeatedly on the floor will cause the magnet to lose its magnetism. HighFour General Sciences Category A: Grades 4 – 5 Round 2 Monday, October 17, 2016 The use of calculator is not required. Answer #17 Answer #18 Explanation: Answer #19 Explanation: Answer #20 Explanation: A Explanation: The correct life cycle of a mosquito is the four-­‐stage cycle of egg → wriggler (or larva) → pupa → mosquito. The first three stages—egg, larva, and pupa—are largely aquatic. These stages typically last 5 to 14 days, depending on the species and the ambient temperature. B An item can be made from one material alone or many different materials. One example of an item which is made from one material is the wooden ruler. An example of an item which is made from more than one material is the computer. D The digestive system works together with the circulatory system. The digestive system digests the food completely in the small intestine. Then the blood from the circulatory system transports the digested food to different parts of the body. B The bones in our body come in different shapes and sizes. Some of them are straight while some are curved. The bones are connected to one another at a joint. However, not all joints allow free movements, such as the immovable joints in the skull. Most joints do allow free movements and they are called movable joints.