2.3 and 2.4

The Need for Cellular Division and Cell Specialization

Text pages 49-53

The Big ideas• Cells are specialized to carry out specific

functions

Vocabulary Words

• Cell specialization• Mucus• Hemoglobin• villi

2.3 The need for cell division

• Why are we composed of many small cells instead of one big cell?– Two objects with the same volume (amount of

space inside) but different shapes have different surface areas

– What are the advantages to being small?

What are the advantages to being small?

Large surface area (a lot of cell membrane, CM) and a small volume

- Messages to travel quicker (nucleus to CM distance)

- Use less energy for transportation - Any cell that does a lot of “work” is small- Efficient/good at taking in lots of nutrients and

getting rid of waste (more areas to use on CM)

What are advantages of being big?

- Do not do a lot of work- More organelles to use- Do not need as many nutrients or produce as

much waste (not as active)- Used for storage or structure

What happens when a cell gets to big?

• When a cell reaches a certain size, it has made a copy of all of its organelles and it divides into two new cells (mitosis)

2.4 Cell Specialization

• Many different types of cells• Each designed to carry out a specific/special

function