★ Must-know
Living things perform seven life processes:
Things can be grouped as:
Further detail
A plant makes oxygen and releases it into the air as a waste product; animals need oxygen to live.
Leaves still attached to a living plant are alive, while fallen leaves are dead even if they are green.
★ Must-know
The roots anchor a plant and absorb water from the soil.
The stem supports the plant and transports water to its other parts.
In sunlight, each leaf makes food for the plant.
The flower makes seeds.
Further detail
📌 All parts of a plant need water, and a plant will die without it.
📌 Only plant parts known to be safe and clean should be eaten; never eat parts of wild plants that you find.
★ Must-know
Further detail
📌 A healthy plant has strong roots, stems, and leaves, while an unhealthy plant may have yellow leaves and wilt.
During germination, the root shoot grows first to get water, and then the stem shoot grows.
A seedling stem growing near a window bends toward the light.
★ Must-know
📌 Without enough water, plants wilt and die.
Further detail
When it is too cold, water freezes into a solid that plants cannot use, and the leaves cannot make food.
When it is too hot, a plant may run out of water, causing its roots, stems, and leaves to dry and break.
Too little water causes wilting; extreme heat or cold can prevent survival.
★ Must-know
🔄 The seed investigation proceeds as follows:
Water moves to every leaf through many very narrow tubes in a tree’s main stem, including in trees over 80 metres tall.
🔄 Water’s journey through a flowering plant is:
Further detail
Air is a mixture of gases made mostly of nitrogen, with some oxygen, which people need to breathe.
Hydrogen sulfide gas smells of rotten eggs, while chlorine gas is yellow.
★ Must-know
📌 Solids keep their shape unless compressed, stretched, twisted, or bent; liquids change shape easily to take the shape of their container; gases spread out to fill the space around them.
Further detail
Examples of solids and liquids are:
Nitrogen and oxygen have no colour, so they cannot be seen.
★ Must-know
📌 A soluble solid dissolves in a liquid, whereas an insoluble solid does not.
📌 In a fair test, one thing is changed, one thing is measured or observed, and the rest are kept the same.
Further detail
A magnet separates magnetic materials from non-magnetic materials.
An insoluble solid in a liquid can be separated easily, while a soluble solid in a liquid is more difficult to separate.
Filter paper has very tiny holes and remains strong when wet, so it does not tear easily.
★ Must-know
Planet Earth is the source of all the materials people use, including manufactured materials made from natural materials.
Most plastic is made from oil found underground, and metals are made from rocks in the ground called ores.
Smelting separates metal from other material in ore by heating and melting the ore.
Examples of carbon-containing fuels are:
📌 Disposable objects are used only once, whereas reusable objects are used many times.
Further detail
Bauxite is an ore used to make aluminium, and hematite is an ore used to make iron.
Natural gas is found underground and is burned for cooking, heating homes, and making electricity; underground oil is heated to produce useful liquids and gases, including petrol and diesel.
Most plastics are strong and flexible and last a very long time; most are made from oil, but plastic can also be made from other carbon-rich materials, including plant and animal materials used to make bioplastic.
Burning carbon-containing fuels produces carbon dioxide, which contributes to global warming.
An opaque object blocks light, creating a shadow.
★ Must-know
📌 Materials that do not let light pass through are opaque, whereas transparent materials let light pass through.
Further detail
In the test table, glass is predicted to be transparent and the test result also identifies it as transparent.
Materials that block light do not make good windows because they prevent people from seeing through them.
Opaque blocks light; transparent lets it pass.
★ Must-know
An object casts a shadow when it blocks light from a light source.
🔄 The investigation proceeds as follows:
As an object moves toward a light source, its shadow gets larger.
Some animals eat only plants, some eat only animals, and some eat both plants and animals.
The arrows in a food chain point in the direction that energy flows, from the food source to the organism that eats it.
Further detail
A shadow can change shape when the object that makes it is moved.
Turning classroom lights off or down makes it easier to observe a toy's shadow during the investigation.
Energy from food enables living things to grow and move, and every part of the body needs energy to work and grow.
In the corn–mouse–cat food chain, energy from the Sun is used by the corn plant to make seeds, passes to the mouse when it eats the seeds, and passes to the cat when it eats the mouse.
A food chain can be represented with pictures or with words and arrows, such as corn → mouse → cat.
Move an object toward the light → its shadow grows.
★ Must-know
Further detail
The fossil pattern shown is from a Pterodactyl, a flying reptile with a long beak, a long neck, claws on its wings, and two feet.
Some insects became fossilized after being trapped in sticky tree gum, which preserved them clearly.
Scientists carefully excavate fossils, sometimes using small tools and paintbrushes to remove soil and sand without damaging them.
Sea or river water can wash away rock and expose fossils that were buried deep underground.
Mary Anning lived by the sea in England over 200 years ago, collected fossils, and became famous as a fossil collector.
Mud impression → rock fossil → careful discovery.
★ Must-know
The Earth, the Sun and the Moon are all spheres, meaning they have the shape of a ball.
Every object with mass has gravity, and an object with more mass has stronger gravity.
Gravity pulls matter towards an object’s centre; Earth’s gravity pulls the Earth’s material inward, the Moon’s gravity pulls its rock inward, and the Sun’s gravity pulls its gas inward, making each spherical.
Further detail
The Moon’s gravity is weaker than Earth’s because the Moon is smaller, while the Sun’s gravity is much stronger than Earth’s because the Sun is much bigger.
Scientists use these kinds of models:
In a clay model of gravity, hands push the clay towards its centre as it is turned, gradually shaping it into a sphere.
Mass creates gravity; gravity pulls matter inward, shaping spheres.
★ Must-know
The Moon takes 29 days to orbit Earth.
Gravity continually pulls the fast-moving Moon towards Earth, keeping it in orbit around Earth.
In the Earth–Moon scale model, every 1,000 km is represented by 1 cm; Earth’s diameter of about 13,000 km is 13 cm, the Moon’s diameter of about 3,500 km is 3.5 cm, and their distance of about 385,000 km is 385 cm.
Further detail
Craters on the Moon are formed when space rocks hit its surface.
In 1969, Neil Armstrong became the first person to walk on the Moon.
Astronauts took three days to travel to the Moon in a rocket.
★ Must-know
The Sun lights only the front half of the Moon, and observers on Earth see different amounts of its light and dark halves as the Moon moves around Earth.
The eight Moon phases are:
📌 The Moon is waxing when the visible light part is getting bigger and waning when it is getting smaller.
Further detail
📌 A gibbous Moon shows more of its light side than its dark side, a first-quarter Moon shows half of each side, and a crescent Moon shows only a little of its light side and lots of its dark side.
The Moon’s phases look different from the northern and southern hemispheres.
Because the Moon orbits Earth, its rising and setting times are a little later each day, and it can be above the horizon during the day or at night.
The Moon orbits Earth; Earth’s rotation makes the Moon appear to cross the sky.
★ Must-know
🔄 Measure an object with a ruler by: placing the ruler’s zero beside one end of the object, putting your eye level with the top of the object to read the scale, checking where the zero mark is because it may not be at the ruler’s end
A results table should have a title and space for each result; a bar chart should have labelled axes with units, a title and bars representing the results in the table.
Further detail
Examples of standard units include:
🔄 Measure air temperature with a thermometer by: holding the thermometer at the top, keeping your eye level with the top of the liquid to read the scale, not holding the bulb, which would make it measure the temperature of your fingers
To use a forcemeter, turn the nut to set it to zero, place the object on it, put your eye level with the pointer and read the scale.
A seedling’s recorded heights over weeks 1 to 5 were 2 cm, 4 cm, 6 cm, 8 cm and 9 cm, respectively.
Take a 49-question practice quiz on Earth Moon and Scientific Models, with every answer explained.
1. Which set of characteristics describes a living thing?
2. A fallen leaf, a leaf attached to a living plant, and a stone need to be classified. Which grouping is correct?
Memorize the key concepts of Earth Moon and Scientific Models with 83 flashcards.
Which seven life processes do living things perform?
Having young, sensing surroundings, needing air, moving, needing water and food, growing, and making waste.
What are the three groups used to classify things by whether they are living?
Alive now, once living but not now living, or never alive.
What do plant roots absorb from the soil?
Water.
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