Student Resources—746

Extra Try at Home Labs
Extra Try at Home Labs
768 STUDENT RESOURCES
Donald Specker/Animals Animals
Prickly Plants
Real-World Question
Why does a cactus have spines?
Possible Materials
• toilet paper roll or paper towel roll
(cut in half)
• transparent tape
• toothpicks (15)
• metric ruler
• oven mitt
• plastic bag or tissue paper
Procedure
1. Stuff the plastic bag or tissue paper into
the toilet paper roll so that the bag or
tissue is just inside the roll’s rim.
2. Stand the roll on a table and hold it
firmly with one hand. Place the oven
mitt on your other hand and try to take
the bag out of the roll.
3. If needed, place the bag back into the roll.
Feeding Frenzy
Real-World Question
How can you observe predation?
Possible Materials
• large jar with metal lid
• hammer and nail
• plant-eating insect
• insect net
• magnifying lens
• leaves, grass, flowers
• water
4. Securely tape toothpicks around the lip
of the roll about 1 cm apart. About 4 cm
of each toothpick should stick up above
the rim.
5. Hold the roll on the table, put the oven
mitt on, and try to take the bag out of
the roll without breaking the toothpicks.
Conclude and Apply
1. Compare how easy it
was to remove the
plastic bag from the
toilet paper roll with
and without the toothpicks
protecting it.
2. Describe the role of a
cactus’ spines.
Procedure
1. Poke tiny holes in the metal lid of a jar
with a nail so the insect has fresh air.
2. Observe a plant-eating insect in the
wild. Collect one for indoor observation
as well.
3. Put leaves, grass, and flowers in the bottom
of the jar. Add a few drops of water.
4. Add the insect. Watch how it behaves.
5. When the experiment is finished,
release the insect back into the wild.
Conclude and Apply
1. Describe the predation behaviors of the
insect.
2. Compare the insect’s behavior in the
wild and in captivity. Did its diet
change?
Adult supervision required for all labs.