Organ Systems

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Atom Noun

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[at-um]

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Atom

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The basic unit of a chemical element that forms the basis of all matter.

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Example: This diagram shows an atom's basic structure: a central nucleus containing protons and neutrons, with electrons orbiting the nucleus in an electron cloud.

Front

Molecule Noun

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[mol-uh-kyool]

Back

Molecule

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A group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

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Example: This diagram shows a carbon dioxide (CO₂) molecule, which is made of one carbon atom and two oxygen atoms chemically bonded together.

Front

Organelle Noun

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[or-guh-nel]

Back

Organelle

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A specialized subunit within a cell that has a specific function, often enclosed within its own membrane.

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Example: This diagram shows an organelle (the green structure) acting like a tiny factory inside a cell, converting food (rice) into usable energy (ATP).

Front

Cell Noun

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[sel]

Back

Cell

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The basic structural, functional, and biological unit of all known living organisms.

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Example: This diagram shows a cross-section of an animal cell, labeling key parts called organelles, which are the basic building blocks of tissues and organs.

Front

Tissue Noun

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[tish-oo]

Back

Tissue

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A group of similar cells from the same origin that together carry out a specific function.

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Example: This image shows that an organ, like the heart, is made of a group of similar cells (cardiac muscle cells) working together, which is called a tissue.

Front

Organ Noun

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[or-gun]

Back

Organ

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A collection of different tissues joined in a structural unit to serve a common function.

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Example: This diagram shows several examples of body organs, such as the heart, lungs, and stomach, which are structures made of tissues that perform specific jobs.

Front

Organ System Noun

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[or-gun sis-tum]

Back

Organ System

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A group of organs that work together to perform one or more specific, complex functions.

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Example: This diagram shows the respiratory system, a group of organs like the lungs and trachea that work together, which is an example of an organ system.

Front

Organism Noun

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[or-guh-niz-um]

Back

Organism

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A complete and individual living being composed of multiple organ systems.

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Example: This diagram shows a dog, an organism, and one of its organ systems (the digestive system), which work together to keep it alive.

Front

Homeostasis Noun

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[hoh-mee-oh-stay-sis]

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Homeostasis

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The state of steady internal, physical, and chemical conditions maintained by living systems for survival.

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Example: This image compares the body's temperature regulation (sweating, shivering) to a home's thermostat (fan, heater) to explain how organisms maintain a stable internal state.

Front

Feedback Loop Noun

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[feed-bak loop]

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Feedback Loop

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The biological mechanisms, such as negative or positive feedback, that are the primary way the body maintains homeostasis.

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Example: This diagram shows two types of feedback loops. The left loop is negative (inhibits stimulus), and the right is positive (enhances stimulus), both using sensors and a control center.