Study Guide

Quick meanings for every word. Pair Tier 3 words with pictures to support newcomers.

Word	Meaning
Energy	What makes things move, grow, warm up, or change. The total amount never increases or decreases — it only changes from one form to another.
Biomass	The total mass of living or once-living material in an area, which stores the energy captured by producers.
Bromothymol Blue Solution	A liquid indicator that turns yellow when more carbon dioxide is dissolved in it, and stays blue-green when less is present.
Chlorophyll	The green pigment in plant cells that absorbs sunlight for photosynthesis.
Chloroplasts	The cell structures where photosynthesis happens, using chlorophyll to convert light energy into sugar.
Guard Cells	Pairs of cells that open and close small pores in a leaf, controlling how gases like carbon dioxide and oxygen move in and out.
Indicator	A substance that changes in a visible way — often color — to signal that a specific chemical change is happening.
Mitochondria	Cell structures that break down sugar to release usable energy — often called the cell's power plant.
Photosynthesis	The process plants use to convert sunlight, water, and carbon dioxide into sugar and oxygen.
Cellular Respiration	The process cells use to break down sugar and release the energy stored inside it, using oxygen and producing carbon dioxide.
Sustainability	Using resources in a way that meets today’s needs without using them up for the future.
Stomata	Small pores on a leaf's surface that open and close to let gases move in and out.
Yeast	A single-celled fungus that breaks down sugar and releases carbon dioxide gas as a byproduct.
Abiotic	The nonliving parts of an environment, like sunlight, water, temperature, and soil.
Aquatic	Living in or related to water, such as a lake, river, or ocean environment.
Biome	A large region defined by its climate and the type of plants and animals that live there, such as a desert, rainforest, or tundra.
Biotic	The living parts of an environment, including plants, animals, and other organisms.
Carrying Capacity	The largest population an environment can support long-term, based on its available food, water, and space.
Climate	The typical weather pattern of a region, measured over many years.
Ecosystem	A community of living things interacting with each other and with the nonliving parts of their environment.
Habitat	The natural environment where a specific organism normally lives, providing the food, water, shelter, and space it needs.
Limiting Factor	A resource or condition — like food, water, space, or temperature — that restricts how large a population can grow.
Organism	Any individual living thing, from a single bacterium to a whale.
Precipitation	Water that falls from clouds to the ground as rain, snow, sleet, or hail.
Radiation	Energy that travels through space as waves or particles — sunlight is a familiar example, but many other objects give it off too.
Resource	Anything an organism needs and uses from its environment, such as food, water, or shelter.
Taiga	A cold forest biome dominated by evergreen trees, found in far northern regions with long winters.
Temperate Forest	A forest biome with four distinct seasons and moderate rainfall, often full of trees that lose their leaves in fall.
Tundra	A cold, treeless biome with a short growing season and permanently frozen ground beneath the surface.
Topography	The shape and features of the land's surface, including its hills, valleys, and elevation.
Tropical Forest	A warm, wet forest biome near the equator that supports an especially large variety of plants and animals.