Why do polar bears have thick white fur?
To stay warm and hide in the snow
Which blood vessels carry oxygen-rich blood away from the heart?
Arteries
What material is usually inside an electric wire to carry the power?
Metal (copper)
What is the main difference between vertebrates and invertebrates?
Vertebrates have a backbone; invertebrates do not
What do we call a consumer that eats both plants and animals?
An omnivore
Which body part helps a fish breathe underwater?
Gills
Why does your heart rate increase when you exercise?
To pump more oxygen to your working muscles.
What kind of electricity makes your hair stand up when you rub a balloon on it?
Static electricity
Why is a whale classified as a mammal and not a fish?
It breathes air with lungs (or feeds its young milk / has hair).
What do we call the path of energy transfer from one organism to another in an ecosystem?
A food chain
Why do birds on different islands have different shapes of beaks?
To eat different types of food.
What is the main function of white blood cells?
To fight diseases and infections
What is refraction?
The bending of light when it passes from one material into another
What makes amphibians different from reptiles?
Amphibians have moist skin and lay eggs in water (reptiles have dry scales and lay eggs on land).
What part of a plant cell absorbs light energy to perform photosynthesis?
The chloroplast
Why do some plants in the rainforest have very wide leaves?
To catch more sunlight under the tall trees.
What gas is a waste product that your respiratory system must remove from your blood?
Carbon dioxide
What are the seven colors that make up white light?
Red, orange, yellow, green, blue, indigo, violet
What do we call an organism that can generate its own internal body heat regardless of the environment?
Endothermic (or warm-blooded).
What causes the four seasons to change on Earth?
The tilt of the Earth's axis as it orbits the Sun.
What is the name of the process where organisms with the best adaptations survive and reproduce?
Natural selection
What is the function of the valves found inside your heart and veins?
To stop blood from flowing backward
What particle with a negative charge moves through a wire to create electricity?
An electron
Why are viruses usually not included in the standard classification system of the five kingdoms?
They are not considered truly alive
What gas makes up the majority of the Sun's mass?
Hydrogen