7-4 The Diversity of Cellular Life Earth – The Living Planet

Unicellular Organisms A single celled organism can do everything that you would expect a living thing to do. They grow, respond to the environment, transform energy, and reproduce. Unicellular organisms dominate the earth.

Multicellular Organisms Cells throughout an organism can develop in different ways to perform different tasks. This is call cell specialization. Examples of specialized animal cells include: Red blood cells Muscle cells Pancreatic cells

Specialized Plant Cells Examples of specialized plant cells include: Stomata Guard cells

Levels of Organization The levels of organization in a multicellular organism are; Individual cells Tissues – group of similar cells that perform a particular function Organs – group of tissues that work together Organ systems – a group of organs that work together to perform a specific function

Levels of Organization Example Individual cell – muscle cells Tissue – smooth muscle tissue Organ – stomach Organ system – the digestive system