Plant and Animal Cells

This is a fun activity where students will create two cells:one animal cell and one plant cell. They will then compare and contrast the two.

MATERIALS

2 Plastic see-through sandwich sacks with twist-ties per student
1 Square hard-plastic sandwich container per student
Lemon gelatin
Various fruits and vegetables such as:
Raisins, plums,small carrots, mandarin oranges, red grapes, cherries, celery
Boiling water, ice cubes, large bowl, spoon, measuring cup

PROCEDURE

1. Boil water and make the gelatin, using ice cubes instead of cold water
for quick cooling. While gelatin is cooling, go to step 2.
2. Have students list the organelles of the cell that they've studied.
3. Have students choose the fruits or vegetables they want to represent
the organelles of the two cells. Ex: raisins for ribosomes, plums for the
two nuclei (one plant, one animal), orange slices for mitochondria, cut
celery for chloroplasts, etc.
The two sacks will represent the plant cell membrane and the animal cell membrane.
The sandwich container will represent the plant cell wall.
4. When gelatin has cooled but not completely set, transfer some gelatin
into each of the two plastic sacks. This represents the cytoplasm in both cells.
5. Have students place their "organelles" into the appropriate cell. When
done, twist-tie the sacks.

EXPLANATION

Students will observe that the plant cell has a cell wall (the sandwich
container) along with a cell membrane (the plastic sack)and chloroplasts. The animal cell has the same organelles, minus the chloroplasts and also the cell wall.

Does Air Weigh Anything?

This easy activity answers the question, "Does air weigh anything?" You may be surprised at the answer!

MATERIALS

2 Balloons of equal size
Balance
(NOTE: If you don't own a balance, the child can make his/her own. Take a ruler that has 3 holes in it. Put one paper clip in each of the 3 holes. Hang the ruler/balance by the middle paper clip on a rod.)

PROCEDURE
1. Ask the child, “Do you think air has mass (weight)?
2. Hang one balloon on one end of the ruler balance by attaching to the paper clip.
3. Blow up the second balloon.
4. Attach the second balloon to the other end of the ruler balance.
5. Compare weights.

EXPLANATION
The fact that air has mass (weight) is an important concept for children to grasp. Air is matter. Matter must satisfy two conditions: it must take up space, and it must have mass (weight). This activity vividly shows that yes, air has mass, because the balloon which was blown up will pull its end of the ruler down. When they are older, they will learn how to calculate, using a periodic table, the mass of different gases. It’s easy!

TRANSPIRATION

This activity is very easy. Plants release water in sunlight to cool themselves. This process is called Transpiration.

MATERIALS

A sunny day
An outdoor plant/tree with lots of green leaves
A plastic grocery bag (not the ziplock type), preferably see-through, with twist-tie

PROCEDURE

1. Place a plastic bag over the end of a plant/tree branch with green leaves in bright sunlight.
2. Twist the tie around the base of the bag to keep out air.
3. You can do this to various trees/plants to compare.
4. Predict what will happen.
5. Wait one to two hours.
6. Remove the bag. Observe.

EXPLANATION

Stomata, which are tiny openings in a leaf, allow gases to enter and leave the plant. They take in carbon dioxide from the air that we breathe out, and use it to make food. They also release oxygen and water. This evaporation of water is called Transpiration. You should see droplets of water inside the plastic bag.