PPSC MCQs

Catalytic converters promote reactions that reduce carbon monoxide, hydrocarbons, and nitrogen oxides.
They require suitable operating temperature.

Biodegradable materials can be decomposed by bacteria and fungi.
Food scraps and paper are common examples.

Composting uses microorganisms to break down organic matter.
The product can improve soil structure and fertility.

Leaks waste substantial water over time.
Repairing them is a simple and effective conservation measure.

Vitamin D promotes calcium and phosphate absorption.
It is important for healthy bones and teeth.

Oxygen accounts for about 21% of dry air.
It supports respiration and combustion.

Vitamin K is required to make several clotting factors.
Deficiency can increase bleeding risk.

The troposphere contains most atmospheric water vapor.
Clouds, rain, and storms form mainly in this layer.

Calcium combines with phosphate in mineralized tissues.
It also supports muscle and nerve function.

Stratospheric ozone absorbs much ultraviolet radiation.
This helps protect living organisms from DNA damage.

Iron is part of the hemoglobin molecule.
Deficiency can reduce oxygen-carrying capacity.

The thyroid incorporates iodine into its hormones.
Deficiency may cause goiter and impaired development.