Levels of organization

By:Zachary Jacobs

Cells

Are the basic unit of structure and function in living things.

May serve a specific function within the organism

Examples- blood cells, nerve cells, bone cells, etc.

Tissues

Made up of cells that are similar in structure and function and which work together to perform a specific activity

Examples - blood, nervous, bone, etc. Humans have 4 basic tissues: connective, epithelial, muscle, and nerve.

Organs

Made up of tissues that work together to perform a specific activity

Examples - heart, brain, skin, etc.

Organ Systems

Groups of two or more tissues that work together to perform a specific function for the organism.

Examples - circulatory system, nervous system, skeletal system, etc.

The Human body has 11 organ systems - circulatory, digestive, endocrine, excretory (urinary), immune(lymphatic), integumentary, muscular, nervous, reproductive, respiratory, and skeletal.

Organisms

Entire living things that can carry out all basic life processes. Meaning they can take in materials, release energy from food, release wastes, grow, respond to the environment, and reproduce.

Usually made up of organ systems, but an organism may be made up of only one cell such as bacteria or protist.

Examples - bacteria, amoeba, mushroom, sunflower, human