7th Grade Integrated Science

Standard 3 – Objective 1

Title: 3-D Cells

Description: Students will create a 3 dimensional model of a cell and then cut it in two to

make a 2 dimensional view.

Materials Needed: (will vary depending on the number of cell parts you wish students to find).

The core curriculum expects students to know nucleus, cytoplasm and cell membrane for

animals cells and the same parts plus chloroplasts and a cell wall for plant cells.

Cytoplasm – yellow playdough ER – red string licorice

Mitochondria – red play dough Ribosomes – pepper

Vacuole – jelly beans Chromosomes – glitter

Chloroplasts – green play dough Cell wall – aluminum foil

Nucleus – play dough Cell membrane – plastic wrap or thin sheets of modeling clay

(Soft taffy or other candies [marshmallows, etc.] may be substituted for play dough organelles).

Unlined drawing paper, student sheet (below), sharp knife for teacher use

Time Needed: (2) 46-minute class periods

Background Knowledge: Cells are usually depicted in 2-Dimensional drawings;

however, this model accurately represents its 3-Dimensional nature. As the students cut their cells in

half, they may miss some parts which would be expected if a real cell was cut in half. Under the

microscope, cell parts are occasionally missing or blocked by other cells.

Procedures:

1. Gather materials: make sure you have different colors of play dough or soft candies

for each organelle. You may assign students to provide some of the materials.

2. Read through student procedures with class members. Write on the board what materials you have for the students to work with.

Provide a place for completed cells to be displayed.

Place students in small groups (3-6 students in each group) and allow time for task.

Safety Note:

5. Have a sharp knife on hand, but only you may use it to cut through cell models.

Scoring Rubric:

Individual participation grade ...... 4

Neatness, accuracy of model ...... 4

Drawings of cells ...... 4

Questions correctly answered ...... 4

Student Sheet Name______Period_____

Title: 3-D Cell Model

Introduction: Cells are very small and cell parts cannot be seen without a microscope.

Scientists often build models of cells to help understand their structure. Every model

has drawbacks and, with cells, it is difficult to understand the true 3-dimensional shape of the

cells from looking at a 2-dimensional picture or other model. In this activity you will build a

model of a cell and compare how it looks in 3-D and 2-D.

Materials: Listen or look at the list your teacher provides.

Procedure:

1. In your groups, decide who will get the materials and send them to get what you need.

2. Plan what you want to put in each cell. You will make a plant and an animal cell.

3. Cut, form, fold, etc. materials until the organelles are in place on the cell membrane or wall. The

finished cells should be larger than a golf ball but smaller than a tennis ball.

4. When all the organelles are in the cytoplasm, carefully fold up the sides and

seal the edges, forming a ball. Draw your 3 dimensional cells in the data table.

5. With a large, sharp knife your teacher will cleanly slices the cells in half to reveal organelles.

6. Draw the 2 dimensional cells and label the organelles.

Data

3-D cells 2-D cells

Animal cell / Animal cell
Plant cell / Plant cell:

Did you label your cell parts?

Analysis:

1. How are plant and animal cells alike? How are they different? (list 3 of each)

2. Describe three functions of a cell and name the structures involved in each function.

3. Why are models important in science?

4. What are two tools or technologies that have aided in the discovery of the cell, organelles,

and their functions?

5. When would the 3 dimensional model be useful for cell study?

6. When would the 2 dimensional model be useful for cell study?

Conclusion: