1. 7th Grade Investigation 4: The Cell Diversity of Life
Ribbons of Life
7th Grade
Investigation 4: The Cell
Diversity of Life

2. Organelle Organelles are the structures inside the cells.
Prokaryotic cells have a few.
Eukaryotic cells have many.
The only organelles common to all cells are ribosomes.
All cells also have a cell membrane and cytoplasm, or the fluid that fills the cells.

3. Prokaryotic and Eukaryotic Cells
The main difference between prokaryotic and eukaryotic cells is the presence of a nucleus in the eukaryotic cells.
Prokaryotic cells do not have a nucleus.
Bacteria are the only kinds of organisms that do not have a nuclei in their cells.
Bacteria are prokaryotes.
All other organisms are eukaryotes.

4. Paramecia and Sheep Cells
Eukaryotic
Live alone
Single-celled organisms.
Their cells generalize (able to do everything for the organism).
Eukaryotic
Depend on complex systems in the sheep to keep them alive.
Not an organism.
Their cells specialize (they do only one thing for the organism).

5. Complex Organisms
Cells in complex organisms often work with other similar cells to perform specific functions.
Masses of cells working together are tissues.
Examples of tissues: bone, muscle, nerves, and endosperm (cotyledon).

6. Life Aquatic
Cells are mostly water, and the environments in which all cells live in is wet.
Organisms that have moved onto dry land have to maintain systems that keep all their cells surrounded by fluid.
Plants and animals transport water through vascular systems and circulatory systems to ensure that the aquatic environment is provided.

7. Plant and Animal Water-Delivery Systems
Plant and animal water-delivery systems also transport other essential resources to and from the cells, including:
Gases
Energy
Waste