system  Every living thing has parts that work together to create a whole – This is called a system. body  Your body works because it runs on an organized set of systems. job  From cells to organs, each part of the system has a job. structures functions  The parts are called structures and the work or jobs they do are called functions.

Cells Tissues Organs Organ Systems Organism

 Single Cells do everything by themselves.  Cells in multicellular organisms divide up the work and depend on other cells to help them do their jobs. life  All living systems are made up of cells, the basic unit of life. Ex. Muscle Cell

ALIKE Groups of cells that look ALIKE, and work together to perform the same function. Ex: Muscle Tissue, Nerve Tissue

3. ORGANS 3. ORGANS: TISSUES FUNCTION Made up of different kinds of TISSUES that work together to do the same FUNCTION. heart Ex: Your heart is an organ made of muscle, nerve and blood tissues

4. ORGAN SYSTEM 4. ORGAN SYSTEM: A group of organs working together to do a certain job. Ex: Circulatory System

5. ORGANISM 5. ORGANISM: All organ systems working together in the body to make a complete organism. Ex: Human

SPECIALIZED CELLS STRUCTURES FUNCTION Cells have different STRUCTURES (sizes and shapes), based on their FUNCTION (job) SMALL BIG Some can be very SMALL and some can be very BIG

Muscle Cells: fibers Structure - long, thin fibers contracts Function – contracts and relaxes to make your body move Bone Cells: matrix Structure – surrounded by hardened minerals that form a matrix and lock together support Function – provide support for the body

Flow through vessels to deliver oxygen to tissues. Need to be small/round to fit through tubes & smooth to not get stuck

Carry messages from brain to body & body to brain Very long (up to 1 meter!) to reach through body and branched at the end to connect to next one

Make a protective barrier to waterproof, block bacteria, viruses, chemicals and UV rays (sun). Geometric shape to stack together like a brick wall.