If you happen to have already made a plant cell model and an animal cell model, comparing these two different types of cells is a natural extension activity. I actually recommend making these cell models simultaneously as they have almost the same list of ingredients. Thankfully, doubling the number of cell models does not double the time!
Unfortunately, creating these two models does not give kids a perfectly clear representation of the differences, but it is a great place to begin a conversation. Some of the differences are very straightforward, like organelles that are in one cell and not the other. For example, the plant cell has green grapes (i.e. chloroplasts) and the animal cell does not. Also, the plant cell has one large water balloon (i.e. vacuole) and the animal balloon has a few small ones.
Other differences are not as obvious. For example, the animal cell uses a round bowl and the plant cell uses a square dish. This is because plant cells tend to be rectangular and animal cells do not. However, if we could have done this demonstration perfecty, we would have pulled the animal cell out of its round bowl after it solidified. (I tried this when my cell was starting to melt a little bit and was unhappy with the result, so I don’t recommend it. It might have worked better if I had done it right after I pulled it out of the fridge.)
However, hopefully the students will notice that the plant cell has a cell wall label on the glass container and the animal cell does not. You can explain to the kids that animal cells do not have cell walls. It is the cell wall that gives plant cells their rectangular rigid structure.
Kids might also be misled by the color of the cytosol. I used one drop of food coloring in each of my cells to make it easier to tell them apart. I used green for the plant cell since plants usually appear green. However, in reality, cytosol is actually colorless. To be more realistic, we could have left the gelatin clear. You can use this discussion as an opportunity to explain to kids that it is actually the chloroplasts that give plants their green color.
Recommended Age Range: Kindergarten, Elementary, Middle School
Time Required: ~30 min (plus the time needed to make the plant and animal cells)
Difficulty: Easy — though making the cell models can be time consuming and requires space in your fridge.
Cost: Free printable. Under $10 in used supplies. I used primarily things we already had in the pantry and fridge, but I did end up buying a small carton of blueberries and a box of gelatin. I recommend switching out items if necessary to avoid buying things if your family won’t enjoy the leftovers.
- If you don’t already have plant and animal cell models, please feel free to follow the tutorials for my plant cell model and animal cell model.
- Have the students examine the two cells and try to determine the differences.
- Discuss with them the differences they see.
Here are some of the differences they may detect on their own or with your assistance.
- The plant cell has green grapes and the animal cell does not. This is because plant cells have chloroplasts, organelles which contain chlorophyll and convert sunlight into energy in a process known as photosynthesis.
- The animal cell has 2 bundles of spaghetti noodles and the plant cell does not. This is because animal cells have centrioles, while most plant cells do not. Centrioles are used for cell division during an animal cell’s reproduction cycle. Plant cells are able to reproduce without centrioles.
- The animal cell has a few small balloons and the plant cell has one large one. This is because, by the time they are done growing, plant cells typically only have one large vacuole that typically takes up more than half the volume of the cell. Animal cells in contrast may have one or more vacuoles, but they are much smaller in size. Vacuoles are used to store water and food. They also help maintain the pressure within the cell.
- The plant cell has a cell wall label and the animal cell does not. This is because plant cells have cell walls which gives plants a rigid structure that allows them to grow upward and outward toward sunlight. Animal cells do not have cell walls. (Note: It would be more realistic if we took away the bowl from the animal cell, but this might be difficult. You could try freezing the animal cell if you wanted to be sure it would maintain it’s shape.)
- The plant cell is square while the animal cell is round. The reason for this is related to the previous observation. Animal cells only have a cell membrane and not a cell wall, so they are typically round in shape. Plant cells have a rigid cell wall, which causes plant cells to typically have more distinct edges and a rectangular shape.
Enjoy your study of plant and animal cells!
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