SCIENCE - YEAR 5 MICROORGANISMS Microorganisms are living things, they are also known as microbes. 1. The following are some types of microorganisms.
2. All microorganisms breathe.
3. Like all microorganisms, bread mould grows.
4. Some microorganisms move. 5. Microorganisms are very small. They cannot be seen with naked eye. We have to use a microscope to see microoranisms. Magnifying glass can be used to observe certain
4. Some microorganisms move. 5. Microorganisms are very small. They cannot be seen with naked eye. We have to use a microscope to see microoranisms. Magnifying glass can be used to observe certain
microorganism such as yeast.
Microscope Magnifying glass Harmful and useful microorganisms 1. Many microorganisms microorganisms are very harmful but some some are useful to human. Useful microorganisms are used in the following processes.
2. Pathogens Microorganisms that caused diseases are called pathogens. Some of the diseases caused by pathogens are as shown below:
3. Some ways to prevent diseases. Keeping ourselves and surrounding clean can prevent many disease caused by microorganism. .
SURVIVAL OF THE SPECIES SURVIVAL OF THE SPECIES Ways different animals ensure the survival of their species Some animals looks after their eggs and young. Examples of such animals are:
Different plants have different ways to ensure the survival of their species 1. Plants have to disperse their seeds far away to avoid competition. 2. Plants depend on four agents to disperse their seeds. These agents are :
(a) Explosive mechanism Example :
Rubber fruit
Flame of the Forest
- When the rubber or flame of the forest, they split open and the seeds are thrown far away. (b)
Wind Example :
Shorea
Lalang
- Shorea and lalang seeds are small and light. - They also have fine hair and wing-like structures to help them be blown away. (c)
Water Example :
Coconut
Water lily
- There are air spaces in the coconut and water lily to help the seeds float in water. (d) Animals Example :
Rambutan
Papaya
- The papayas are fleshy and brightly coloured fruits which are eaten by animals. The importance of survival of the species 1. Survival of living things is the wise and systematic management of living things. This include efforts to restore the natural state of the living things. 2. Survival of species is important to ensure that there will be enough natural resources for the future generations. 3. The consequences of a certain species of animals and plants becoming extinct are: (a) shortage of food resources (b) other species may also face extinction.
FOOD CHAIN AND FOOD WEB Food chains 1. A food chains - shows how organisms depend on one another for food - shows the relatioship in one direction only - always starts with green plants called producers 2.
(a) (b) (c) (d)
The paddy plant is the producer. The grasshopper is the primary consumer. The frog is the secondary consumer. The eagle is the tertiary consumer.
(a) (b) (c) (d)
The plant is the producer. The deer is the primary consumer. The fox is the secondary consumer. The tiger is the tertiary consumer.
3. Herbivores are animals that eat plants and parts of plants.
Example :
4. Carnivores are animals which eat other animals. Example :
5. Ombivores are animals which eat both plants and other animals. Example :
Food webs 1. An organism may be a part of more than one food chain.
2. A change in the population of one species affects the populations of other species. 3. For example, if the number of rats increases, the number of paddy plants will decrease and the number of grasshoppers, birds and
eagles will decrease, because there is no or little food. However, the number of owls will increase and so will the number of snakes because there are more rats to eat. 4. Some animals eat only one type of food. Example :
The panda eats only bamboo shoots.
The koala eats only eucalyptus leaves.
The pangolin eats only ants. 5. These animals will die out and become extinct when their food source is not available.
ENERGY 1. Forms of Energy
Uses of energy: 1. Energy is used to: (a) carry out life processes such as breathing and growth
(b)
move objects
(c)
melt object
(d) dry clothes and other things
(e) cook food
2. The following are sources of energy.
Energy can be transformed from one form to another Energy can be trasformed from one energy source to another.
Potential energy changes to kinetic energy.
Chemical energy changes to light energy and heat energy.
Renewable and non-renewable energy 1. Renewable energy can be replenished after being used. 2. Examples of renewable energy sources are:
3. Non-renewable energy cannot be replenished when it is used up. 4. Examples of non-renewable energy sources
are:
5. We have to use energy wisely. 6. We should use as little energy as possible because: (a) Some energy sources cannot be replenished when used up (b) To save cost (c) To avoid wastage (d) To reduce pollution 7. We should always use renewable energy sources instead of non-renewable energy sources wherever possible.
ELECTRICITY ELECTRICITY Sources of electricity Below are sources of electricity : - Electricity is the effect which results from moving or stationary electric charges. - Electricity can be generated from an electric generator.
Series circuits and parallel circuits 1. The components in a circuit are :
2. The two types of circuits are:
Safety precautions We must not:
LIGHT SOURCES OF LIGHT
Light travels in a straight line 1. Light travels in a straight path.
2. A shadow is formed when the path of light is blocked.
3. The closer the object to the light source, the bigger the shadow formed.
4. The position of the light source causes different shapes of shadows to be formed.
Light can be reflected
1. Light can be reflected
2. The principle of the reflection of light is used in:
HEAT Temperature is an incator of degree of hotness. We measured temperature with a thermometer. 1. When a substance gains heat, it will become warmer. When it loses heat, it will become cooler.
-
The iron rod gains heat. It becomes hot. Its temperature rises. Heat will be trasferred from A to B
- The iron rod loses heat. - It becomes cool. - Its temperature drops. 2. Temperature can be measured with a thermometer.
3. The correct technique to measure temperature: - Use a thermometer - Place the bulb of the thermometer into the water. - The bulb of the thermometer should not touch the base of the beaker. - Your eye must be at the same level as the mercury when taking the reading.
4. The unit for temperature is degrees Celcius ( oC ) .
Effects of heat on matter
1. Heat will make matter hotter. 2. Matter expands when heated. 3. Matter contracts when cooled.
At room temperature, the metal ball can go through the ring.
The heated metal ball expands. It cannot go through the ring.
3. The principle of expansion and contraction of matter is applied in: (a) An electric cable is installed loosely to prevents it from snapping when it contracts in cold weather.
(b) The gaps in railway tracks allow for expansion in hot weather.
(c) A tight bottle cap can be loosened by placing it in hot water.
(d) Concrete slabs on pavements have gaps to allow for expansion.
STATES OF MATTER Matter exists in the form of solid, liquid or gas (a) Solid - A solid has (i) a fixed shape (ii) a fixed volume (iii) mass - Some solids such as rock, wood and metal are hard. - Some solids such as cotton, sponge and cloth are soft. - There are light solids such as cork and paper. - There are heavy solids such as iron and rock. - Some different shapes are such as:
(b) Liquid - A liquid (i) does not have a fixed shape (ii) has a fixed volume (iii) has mass
- A liquid takes the shape of the container it is in. - A liquid flows from a higher place to a lower place. - A liquid occupies space.
(c) Gas - A gas (i) does not have a fixed shape (ii) does not have a fixed volume (iii) has mass - The shape of a gas is indefinite. A gas takes the shape of the container that holds it.
- A gas does not have a defined volume. Based on figure, when the seal of the gas jar is removed, the gas fills up the whole jar.
- A gas can fill up a whole space. A gas flows in all directions. - A gas can be compressed. When a gas is compressed, its volume decreases. Matter can change from one state to another 1. Matter can exist in three states (i) solid (ii) liquid (iii)gas.
2. Evaporation and boiling both change liquid into gas. 3. Evaporation happens at any temperature below the boiling point. Boiling only occurs at the boiling point. 4. Evaporation can be speeded up if: (a) it is windy (b) a larger area is exposed (c) the temperature is higher 5. Factors that affect the rate of evaporation (a) Temperature - higher temperature speeds up evaporation (b) Wind - windy surrounding speeds up evaporation (c) Surface area - Larger surface area speeds up evaporation
Water cycle The formation of clouds and rain (Water cycle)
(a) The heat from the sun warms up seas, rivers and lakes. (b) Water evaporates and becomes water vapour. (c) Water vapour rises. (d) As water vapour reses, it cools and condenses. Water droplets are formed. Many water droplets collect and form a cloud. (e) When a cloud becomes heavy with water droplets, rain forms and falls down to earth. (f) Rainwater falls on seas, rivers and lakes. Rain also falls into the soil. The rain that falls into the soil flows to the seas, rivers and lakes. (g) The cycle begins again.
The importance of water resources 1. Water is a very important resource. All living things need water. 2. We should keep our water resources clean.
ACID AND ALKALI Understanding the properties of acidic, alkaline and neutral substances Acidic Substances 1. An acidic substance has a sour taste. 2. It changes blue litmus paper to red. 3. If the acidic substance is tested with a red litmus paper, no colour change will be seen.
4. A strong acid is corrosive and can burn the skin.
5. The picture shows a few acidic substances.
Alkaline Substance 1. Alkaline substances taste bitter and feel 'soapy' to touch. 2. It changes red litmus paper to blue. 3. If the alkaline substance is tested with a blue litmus paper, no colour change will be seen. 4. A strong alkali is corrosive and can burn the skin.
5. The picture shows a few alkaline substances.
Neutral Substance 1. A neutral substance does not have an acidic or alkaline property. 2. It will not change the colour of blue or red litmus paper. 3. If an acidic substance is mixed with an alkaline substance, a neutral substance is formed.
Effect of Neutral substance on litmus paper.
4. The picture shows a few neutral substances.
CONSTELLATION Understanding the constellation 1. A constellation is a group of stars in the sky that appears to form a certain pattern. 2. These stars look brighter and more obivious than the other stars. 3. Various patterns of the constellations have been found. For example, the Scorpio constellation look like a scorpion and the Orion constelllation look like a hunter.
4. There are around 88 types of constellations. 5. The diagram below show a few constellations. (a) Orion
- It can be seen between December - February around 8.00pm to 10.00pm.
(b) Scorpion
- It can be seen between June to August around
8.00pm to 10.00pm. (c) Big Dipper
- It can be seen between April - June around 8.00 pm to 10.00 pm. (d) Southern Cross
- It can be seen between April - June around 8.00 pm to 10.00 pm. 6. Twelve of the constellations make up zodiac signs which consists of Capricorn, Aquarius, Pieces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio and Sagittarius. 7. The zodiac is also called the seasonal constellations. It appears at different times of the year. 8. Some constellations can be seen all year round. They are known as the circumpolar constellations. These constellations are important. (a) for navigation.
(b) for learning about other stars. (c) as a calendar. 9. In olden times, sailors and explorers used the constellations to navigate. The constellations that were often used are Ursa Major, Cygnus and Orion. These constellations are used because they always give directions accurately.
10. Nowdays, most sailors use the compass instead of the constellations for navigation. 11. Besides navigation purposes, constellations are also used by astronomers to study other stars. They can also be used as calendars by observing their position. 12. The importance of constellations are (a) to show directions (b) to indicate the time to carry out certain activities, e.g. planting sea son.
THE EARTH, THE MOON AND THE SUN
Movements of the Earth, Moon and Sun (a) The Earth rotates on its axis from west to east. It takes 24 hours to complete one rotation. (b) The Earth also revolves around the Sun. It takes about 365 days to make one complete revolution. (c) The Moon revolves around the Earth. It takes 27
1 days to make one complete revolution. 2
Occurance of day and night 1. Occurence of day and night is due to the rotation of the Earth on its axis.
2. The part of the Earth that is facing the Sun is experiencing daytime. 3. The part of the Earth that is not facing the Sun is experiencing night-time.
Phases of the Moon 1. When observed at night, the shape of the Moon appears to change. Thisis known as the phases of the Moon. 2. The phases of the Moon occurs because only the part of the Moon that reflects sunlight can be seen from the Earth.
3. The same phase of the Moon is seen every 29 1 days. 2
STRENGTH AND STABILITY STRENGHT AND STABILITY Shapes of objects in structures 1. Objects appear in various shapes, they include cube, cuboid, cylinder, cone, sphere and pyramid.
A mosque
A temple
2. All buildings are constructed based on those basic shapes. Example : (a) The mosque (b) Petronas Twin Tower (c) KL Tower 3. When designing buildings, the shape of the structure chosen is important to ensure its strength and stability.
A house made of concrete is stronger than a house made of wood. 4. Most buildings have more than one in their design.
Strength and stability of structures. 1. A strong and stable structure does not break or collapse easily. 2. The strength and stability of a structure depends on: (a) The material (b) Position of the centre of gravity (c) Base area (d) Height
3. Least Stable
(a) When the tray is tilted, P falls first, followed by Q then R. (b) P is the least stable. R is the most stable. (c) R is the most stable because its centre of gravity is the lowest.
Building Q is more stable than building P. (a) When the tray is tilted. X falls first, followed by Y then Z. (b) X is the least stable. Z is the most stable.
