Pakistan MCQs

Most atmospheric ozone is concentrated in the stratosphere.
It absorbs much of the Sun's harmful ultraviolet radiation.

A water molecule contains two hydrogen atoms and one oxygen atom.
Its formula is H₂O.

Common salt is sodium chloride.
Its chemical formula is NaCl.

Human cells use oxygen in cellular respiration.
The process releases energy from food molecules.

The cerebellum coordinates movement, posture, and balance.
It lies at the back of the brain.

Solar radiation drives weather, climate, and photosynthesis.
Other energy sources are much smaller for the surface system.

Human body cells normally contain 46 chromosomes in 23 pairs.
Reproductive cells contain 23 chromosomes.

Wind turbines convert the kinetic energy of moving air into electricity.
It is a renewable energy source.

Sunlight helps the skin produce vitamin D.
This vitamin supports calcium absorption and bone health.

Carbon dioxide is a major greenhouse gas released by fossil-fuel use.
It traps heat in Earth's climate system.

Severe vitamin C deficiency causes scurvy.
Symptoms include weak gums, bruising, and poor wound healing.

Recycling processes used materials into new products.
It can reduce waste and demand for raw resources.