A
Which key function is provided by the human skull?
Protecting the brain
Which type of skeleton is located on the outside of an insects body?
exoskeleton
Which organism relies on a fluid-filled cavity under pressure as its skeleton? earthworm/starfish
earthworm
Which skeletal structure surrounds and protects the heart and lungs?
Ribcage
Which object is classified as a natural luminous light source? The Sun/moon
The Sun
Which physical trait distinguishes all vertebrate animals from invertebrate animals?
Presence of an internal bone
Why is it important to follow dosage instructions when taking medicine?
To ensure safety and effectiveness
How are human eyes able to see a non-luminous object like a desk?
Light reflects into the eye
Which type of surface produces the clearest mirror-like reflection?
smooth and shiny
Which type of material blocks all light from passing through creating a shadow?
opaque
What happens to the triceps muscle when the arm is bent at the elbow?
It relaxes
Which type of organism is a common cause of infectious diseases in humans?
Harmful bacteria
What happens to the shadow on a screen when the light source moves closer to the object?
The shadow becomes larger
Which motion of Earth causes day and night?
rotation on its axis
Which component provides electrical energy in a simple circuit?
cell or battery
Why do skeletal muscles work in pairs?
Muscles can only pull
Why do shadow lengths change outside between early morning and midday?
The Sun's position in the sky changes
What is the primary purpose of a switch in an electrical circuit?
opening or closing circuit gaps
Is wet thread a good electrical conductor or electrical insulator?
electrical conductor
Why are copper electrical wires wrapped in a plastic outer coating?
Plastic acts as an insulator
How does a vaccine protect the body against infectious diseases?
It trains the immune system
Why is touching electrical switches with wet hands dangerous?
Tap water conducts electricity
What happens to a bulb's brightness when an extra cell is added in series?
The bulb glows brighter
What happens to two bulbs when connected in series to a single cell?
Both bulbs become dimmer
Why does electric current stop flowing through an open circuit?
The conductive path is broken