Overarching Question: What makes something alive? Guiding Question: How do cells heal your body?

Multiplying by Dividing: ■ Procedure: ❑ Get a half sheet of paper and a scissors. ❑ Use the scissors to cut your paper in half, then count the number of paper squares you have. ❑ Stack the paper squares up and cut them in half again. Then count the number of squares. ❑ Repeat this procedure 3 more times. Count the squares each time.

Cell Division Activity Chart Number of times cut in half Number of paper squares Predict how many paper squares you would have next!

Think about it… ■ The activity modeled cell division (when one cell splits into two). ❑ Why is it important for cells to divide? ❑ How does a person get taller? ❑ How does a broken bone heal itself? ❑ Why do cuts and scrapes disappear? ❑ What is the main purposes for cell division?

Topic : Cell Division - Mitosis ■ Questions: ■ Why do cells need to divide? ■ Notes: ■ 3 Reasons Cells Divide: ❑ Growth – So organisms can grow and develop. ❑ Maintenance – To replace worn out or dead cells. ❑ Repair – To fix cuts and scrapes and heal body parts. Page 39

Topic : Cell Division - Mitosis ■ Questions: ■ Notes: ■ Interphase: when cells grow and copy their DNA. ■ Cells spend most of their time in interphase. ■ Mitosis: When 1 cell divides and becomes 2 cells. Page 39

Topic : Cell Division - Mitosis ■ Questions: ■ What are the stages of cell division? ■ Notes: ■ Mitosis has 5 stages or phases: ■ Cells begin in Interphase. ■ Stage 1: Prophase ■ Stage 2: Metaphase ■ Stage 3: Anaphase ■ Stage 4: Telophase ■ Stage 5: Daughter cells Page 39

Multiplying by Dividing Lab: Guided Activity. ■ Interphase: ■ Stage 1: Prophase – mitosis begins. Nucleus

Multiplying by Dividing Lab: Guided Activity. ■ Stage 2: Metaphase – chromosomes line up in the middle of the cell. ■ Stage 3: Anaphase – chromosomes move to different sides of a cell.

Multiplying by Dividing Lab: Guided Activity. ■ Stage 4: Telophase – the cell begins to divide. ■ Stage 5: Daughter cells – 2 cells are created and go back to interphase. 2 new Nuclei

■ Outline the cell membrane of the cells in these colors: ■ Prophase cells—red ■ Metaphase cells—green ■ Anaphase cells—yellow ■ Telophase cells—orange ■ Interphase cells—purple Multiplying by Dividing Lab: Guided Activity.

Cell Cycle – The Stages of Cell Division

Cell Division in a Plant’s Root ■ Why would you be able to see cell division occurring in a plant’s root tip?

Cell Division Wrap-up: ■ You should be able to answer these questions about cell division ❑ Why is it important for cells to divide? ❑ How does a person get taller? ❑ How does a broken bone heal itself? ❑ Why do cuts and scrapes disappear? ❑ What is the main purposes for cell division?