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