Upload
nancy-webb
View
280
Download
3
Tags:
Embed Size (px)
Citation preview
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
Copepod (1mm)
P/S: why do cells of a multicellular organismneed to communicate?
volvox
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
lungsPS: discuss the functions of the organs listedhere
liver
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 ……………………… Cells specialize because………… Cells cooperate because……….
Onion tissue