2024-2025 8th Grade Science STAAR Vocabulary Review

law of conservation of mass

• In chemical changes, the total mass of the materials does not change; the total mass of the reactants is equal to the total mass of the products.

• Mass can be created or destroyed in chemical reactions.

• The total mass of products is always greater than the total mass of reactants.

• Atoms can change their type during a chemical reaction.

gene

• segment of DNA that encodes for specific and complete proteins

• a type of RNA that helps in protein synthesis

• a protein that regulates gene expression

• a sequence of amino acids in a protein

closed system

• a physical system that allows free transfer of matter and energy

• a physical system that does not allow transfer of matter in or out, although energy can flow into and out of the system

• a system that is completely isolated from its surroundings

• a system that only allows energy transfer but not matter transfer

chemical equation

• A representation of a physical change

• A description of a chemical reaction that includes all reactants and products

• A formula that shows the structure of a molecule

• An equation that balances the number of atoms on both sides

hydrosphere

• the system on Earth that contains all of the liquid and frozen water on Earth's surface as well as groundwater below the surface and water vapor in the atmosphere

• the layer of gases surrounding the planet

• the solid outer layer of the Earth

• the region of the Earth where living organisms exist

force

• a push or pull between two objects

• a type of energy

• the speed of an object

• the mass of an object

population

• a group of interbreeding organisms of the same species within an environment

• a collection of different species living in the same area

• the total number of organisms in a specific area

• the number of individuals of a species that can survive in a given environment

ecosystem

• the biotic and abiotic resources to support specific populations in a community

• a group of organisms of the same species living in a specific area

• the physical environment where organisms live

• the interactions between different species in a habitat

inherited trait

• specific variations in the characteristics of organisms received from a parent or ancestor by genetic transmission

• a characteristic that is acquired through environmental factors

• a trait that is only present in one generation

• a feature that is randomly assigned at birth

ocean current

• horizontal and vertical streams of circulation in ocean waters that are produced by gravity, wind friction, temperature differences, and water density variation in different parts of the ocean; move in predictable patterns around Earth

• random movements of water caused by marine life

• the rise and fall of sea levels due to gravitational forces

• the flow of water in rivers and lakes