Which organ system is responsible for carrying messages to and from the brain?

• Digestive system

• Nervous system

• Circulatory system

• Respiratory system

Which part of the plant produces seeds?

• Root

• Stem

• Leaf

• Flower

Which of the following is a vertebrate?

• Butterfly

• Fish

• Ant

• Spider

Which of these is a heterogeneous mixture?

• Salt water

• Vinegar

• Oil and water

• Sugar solution

What do you call the force that pulls objects toward the center of the Earth?

• Magnetism

• Friction

• Gravity

• Energy

Which energy transformation happens when you use a flashlight?

• Heat to sound

• Light to heat

• Chemical to light

• Mechanical to sound

Which layer of the atmosphere protects us from harmful rays of the Sun?

• Troposphere

• Ozone layer

• Stratosphere

• Mesosphere

The Earth takes __________ days to complete one revolution around the Sun.

Which celestial body is the center of the solar system?

• Moon

• Sun

• Earth

• Jupiter

Which of the following is a nonrenewable energy resource?

• Solar

• Coal

• Wind

• Water