7-4 the diversity of cellular life

Unicellular organisms Unicellular organisms perform all of life’s essential functions within a single cell. There are far more unicellular life forms than multicellular ones. Yeast cell

Multicellular organisms Cell specialization: Cells develop in different ways to perform different tasks for the whole organism. Cells communicate and cooperate with each other volvox P/S: why do cells of a multicellular organism need to communicate? Copepod (1mm)

Specialized cells Red blood cells: transport O2 Pancreatic cells: produce enzymes to digest food. Guard cells open & close the stomata to exchange gases and water in plants. Islet cells: pancreas

Levels of organization Within an organism are 4 levels of organization 1. cell 2. tissue 3. organ 4. organ system WB: what level of organization is our brain?

Tissue A group of similar cells that perform a particular function. Animal tissues: epithelial, nervous, muscle, & connective

Organs Made of groups of different tissues to perform a specific function for the body ex: heart, lung, stomach, liver Heart liver PS: discuss the functions of the organs listed here lungs

Organ system A group of organs working together to perform a specific function. Specialization and interdependence is one of the remarkable attributes of living things. WB: which organs are found in the digestive system?

Summary Today’s topic was……………… A tissue is ……………………… Onion tissue Today’s topic was……………… A tissue is ……………………… Cells specialize because………… Cells cooperate because……….