Levels of Organization

Cell—Basic unit of structure and function in organisms. Some organisms, like bacteria and protists, are unicellular (made entirely of one cell). Some organisms, like fungi, plants, and animals, are multicellular (made of many cells). Bacteria have prokaryotic cells. Protists, Fungi, Plants, and Animals have eukaryotic cells. In multicellular organisms, cells exhibit cell specialization. They take on specific jobs and look different from each other. The cells also exhibit division of labor. They split up the work of the organism.

Levels of Organization Tissues—Groups of similar cells that work together to perform a specific function. 4 major tissue types in animals Epithelial tissue Connective tissue Muscle tissue Nervous tissue

Levels of Organization Organs—structures made of different types of tissues that work together to perform a specific function. Examples Heart Lungs Stomach Small intestine Liver Large Intestine Gall Bladder Plant Roots Plant Stems Plant Leaves

Levels of Organization Organ Systems—Groups of organs that work together to perform a specific function. Examples: Digestive system Circulatory system Respiratory system Nervous system Muscular system Skeletal system Integumentary system (skin) Vascular system in plants

Levels of Organization Organism—A complete, individual living thing. Examples: A single person A single plant A single bacterium A single protist