Cells and SizeDo cells have size limits?

Cells can range from 2µm to 200µm (10⁻⁶m).

µm = millionth of a meter or 0.000001m

Most eukaryotic cells are about 10µm. Not visible with the naked eye.

Let's put this into perspective!!

One size for all?

This means that an infant’s cells are the same size as an adult or teenager.

Eukaryote cells all have similar sizes. They increase cell numbers to grow.

Why do Eukaryotes have so many cells? Why do we not have just 1 cell or 10 cells?

There is still lots of cell variety!!!

One size for all?

A few Cell types

Muscle Cells

Epithelial Cells (skin)

Nerve Cells

These cells may look very different, but are all about the same size.

Shapes may change, but sizes are constrained!! Why??

A few Cell types

Red and White Blood Cells

Plant cells

Microvilli in the small intestine

Branches in Lungs

Anemones many tentacles

Trees and their broad/flat leaves

Ways organisms increase Surface Area

Increasing Surface Area for individual cells is also important.

Consider :

◦ What are all these adaptations trying to accomplish for the organism?

Ways organisms increase Surface Area

What measurements represent the cell membrane? The cytoplasm?

Does the distance from the center increase or decrease from model to model?

Which cell is best able to interact with its environment?

How can cells increase their total surface area to volume ratio?

Questions to Think About