MCAS Grade 5 Science key terms

A body part or behavior that helps a living thing survive in its habitat. For example, thick fur keeps an animal warm in cold places, and a beak shape helps a bird get certain foods.

The place where a plant or animal naturally lives and finds what it needs: food, water, shelter, and space. A pond, a forest, and a desert are different habitats with different conditions.

All the living things in an area together with the nonliving parts they interact with, such as soil, water, air, and sunlight. Changes to one part can affect the others.

All the members of one kind of living thing that live in the same area at the same time. A pond might hold one population of frogs and another population of cattails.

All the different populations of living things that share an area and interact with one another. The plants, insects, birds, and fish in a pond make up its community.

A living thing that makes its own food using energy from sunlight, usually through photosynthesis. Green plants and algae are producers, and they are the base of most food chains.

A living thing that cannot make its own food and must eat other living things to get energy. Animals, fungi, and many bacteria are consumers.

A living thing such as a fungus or bacterium that breaks down dead plants and animals and wastes, returning nutrients to the soil. Decomposers help recycle matter in an ecosystem.

A model showing the path energy takes as one living thing eats another, usually starting with a producer. An arrow points from the food to the eater, showing the direction energy flows.

A model of several connected food chains in an ecosystem, showing that many animals eat more than one kind of food. It gives a fuller picture of how energy moves through the community.

The process in which green plants use sunlight, water, and carbon dioxide to make sugar for food and release oxygen. It takes place mainly in the leaves and needs the green pigment chlorophyll.

The green pigment inside plant leaves that captures light energy for photosynthesis. It is what gives most leaves their green color.

A gas in the air made of carbon and oxygen. Plants take it in through their leaves and use it during photosynthesis, and animals breathe it out.

A gas in the air that most living things need to release energy from food. Plants release oxygen during photosynthesis, and animals take it in when they breathe.

A characteristic passed from parents to offspring through genes, such as eye color in people or flower color in plants. Inherited traits are present from birth and are not learned.

A way of acting that an animal picks up through experience or teaching rather than being born with it. A dog learning to sit on command is an example.

A behavior an animal is born knowing how to do without being taught, such as a bird building a nest or a sea turtle heading for the ocean. Instincts help animals survive.

The stages a living thing passes through from the start of life to producing offspring of its own. A butterfly's life cycle includes egg, larva, pupa, and adult stages.

A major change in body form that some animals go through as they grow. A frog changes from tadpole to adult, and a butterfly changes from caterpillar to adult.

The idea that living things with traits that help them survive and reproduce tend to pass those traits to more offspring, so helpful traits become more common over time.

A substance living things need to grow and stay healthy, such as minerals taken from the soil by plant roots. Decomposers return nutrients to the soil.

Anything that has mass and takes up space. Matter can be a solid, liquid, or gas, and it is not created or destroyed when it changes form.

The amount of matter in an object, usually measured with a balance in grams or kilograms. Mass stays the same even if the object's shape or location changes.

A measure of how strongly gravity pulls on an object, which can change with location. An object has the same mass on the Moon but less weight there.

A state of matter that has a definite shape and a definite volume. The particles in a solid are packed closely together and vibrate in place.

A state of matter that has a definite volume but takes the shape of its container. The particles in a liquid are close together but can slide past one another.

A state of matter that has no definite shape or volume and spreads out to fill its container. The particles in a gas are far apart and move quickly.

The rule that matter is not created or destroyed during a change; it only changes form or is rearranged. The total mass stays the same in a closed container.

Two or more substances combined without a chemical reaction, so each keeps its own properties. Trail mix and salt water are mixtures that can often be separated by physical means.

A mixture in which one substance dissolves evenly in another, such as sugar in water. The dissolved substance seems to disappear but is still there.

The change of a liquid into a gas, which happens when particles gain enough energy to escape. Puddles dry up because their water evaporates into the air.

The change of a gas into a liquid when it cools. Water droplets forming on the outside of a cold glass come from water vapor in the air condensing.

The movement of water between Earth's surface and the air through evaporation, condensation, precipitation, and collection. The same water is used again and again.

Water that falls from clouds to Earth's surface as rain, snow, sleet, or hail. Precipitation returns water that evaporated from the surface back to the ground.

The force that pulls objects toward each other, and that pulls objects toward Earth's center. Gravity keeps the planets in orbit and makes dropped objects fall.

A push or a pull that can change an object's motion or shape. Forces have a size and a direction, and they can be measured with a spring scale.

A force that resists motion when two surfaces rub against each other, producing heat. Rough surfaces create more friction than smooth ones.

A change in an object's position compared with a reference point over time. An object's motion changes only when a force acts on it.