Life Science Project: Model of a Cell

This project can be used as part of an assessment for a life science unit on cells. Prior to this assignment, students will have learned the difference between plant and animal cells and the structure and function of the cellular organelles.

The project will be done outside of class, and students should be given one to two weeks to complete it. It is strictly forbidden to use commercial model kits. Students should spend little or no money on supplies, and the models should be made out of common materials that they find at home.

Some possibilities for materials include:

• Jello
• pasta of different shapes and colors
• candy
• pipe cleaners
• marbles
• beads
• buttons
• cardboard
• Styrofoam
• modeling clay or paper mache.

Student Requirements

Students should indicate whether their model is of a plant or an animal cell. The model must include all of the organelles and components listed below. Each part of the model must be clearly labeled. Along with the model, students will complete and turn in a brief report describing each of the components of the cell and their functions.

• Plasma membrane - the thin outer boundary of the cell, composed of proteins and lipids.
• Cytoplasm - the gel-like substance that fills the inside of the cell, surrounding the organelles.
• Endoplasmic reticulum (ER) - the membrane network involved in transporting materials throughout the cell. Rough endoplasmic reticulum has ribosomes attached, and smooth endoplasmic reticulum does not have ribosomes attached.
• Golgi bodies - appearing like stacks of pancakes, they form a network of membranes that store, package and transport proteins and lipids around the cell or secrete them to the outside of the cell.
• Ribosomes - the protein factories of the cell, where protein synthesis takes place.
• Nucleus - large organelle surrounded by the nuclear membrane; it controls the cell’s activities and contains the chromosomes, which are made of DNA and protein.
• Mitochondria - the powerhouse of the cell, supplies the cell with energy in the form of ATP.
• Lysosome - the cell’s digestive system, contains digestive enzymes that break down old parts of the cell so their molecules can be recycled.
• Vacuole - a space surrounded by membrane that stores food or waste products; vacuoles are much larger in plant cells than in animal cells.
• Cell wall (plant cells only) - the rigid outer border of the cell, made of cellulose, that provides structure and protection.
• Chloroplast (plant cells only) - large, oval-shaped green organelles that contain chlorophyll; where photosynthesis takes place.

Assessment

Here are some assessment criteria for this assignment:

• Did the student indicate whether it was a plant or animal cell?
• Were all of the required organelles and cellular components included?
• Was each component labeled?
• Were the components represented correctly? (Cell membrane or cell wall around the outside, relative sizes correct, such as the nucleus should be larger than the vacuoles and lysosomes, etc.)
• Did the student turn in a report with a correct summary of descriptions of the components?