earth science
biology
the solar system
plants and animals
elements
100

This is an earthquake that occurs underwater and can create large waves in the ocean.

tsunami

100

This organ pumps blood throughout your body.

the heart

100

who goes into space?

astronauts

100

This part of the plant helps it absorb water from the ground.

The roots

100

what is bad to breathe in?

carbon dioxide

200

This is the gas that makes up most of Earth's atmosphere and is essential for breathing.

oxygen

200

this system helps you breathe by bringing in oxygen and releasing carbon dioxide.

respiratory system

200

The Earth orbits around this star.

The sun.

200

A cold-blooded animal that lives in water and breathes through gills.


A fish

200

This element is found in the air and is also part of water (H2O).

hydrogen

300

This is a renewable resource used for growing plants and crops.

soil

300

These single-celled organisms can live in many environments and are sometimes harmful to humans.

bacteria

300

This planet is known for its beautiful rings.

Saturn

300

These animals lay eggs and are cold-blooded.

reptiles

300

This element is known for its reddish color and is used to create pennies.

copper


400

This is the outermost layer of the Earth, made up of solid rock.

the crust

400

This is the largest organ in the human body.

skin

400

This planet is known as the "Red Planet" because of its reddish appearance.

mars

400

This process is how plants make their own food using sunlight.

photosynthesis

400

This soft rock is often used for carving statues and comes in a variety of colors. usually white and grey

marble

500

The Earth's orbit around the Sun takes about this many days.

365 days

500

This part of the nervous system includes the brain and spinal cord.

the central nervous system

500

What is the closest planet to the Sun?

Mercury

500

This is an adaptation that allows animals like bats and dolphins to navigate by making sounds and listening to the echoes.

echolocation

500

This is the hardest known natural material found on Earth.

a diamond