PPSC MCQs

The embryo requires energy for growth.
Respiration releases this energy from stored food.

Roots secure the plant in soil.
Root hairs increase absorption of water and minerals.

The heart contracts rhythmically to circulate blood.
It supplies tissues with oxygen and nutrients.

The heart has two atria and two ventricles.
The chambers separate oxygenated and deoxygenated blood.

Arteries carry blood away from the heart under pressure.
Most carry oxygenated blood, with pulmonary arteries as an exception.

Veins return blood to the heart.
Many contain valves that help prevent backflow.

Capillary walls are only one cell thick.
This allows diffusion of gases, nutrients, and wastes.

Photosynthesis stores light energy in glucose.
Oxygen is released as a by-product.

Red blood cells contain hemoglobin.
Hemoglobin binds and transports oxygen.

Carbon dioxide supplies carbon for glucose formation.
It enters leaves mainly through stomata.

White blood cells identify and attack pathogens.
Different types act through phagocytosis or immune responses.

Splitting water during photosynthesis releases oxygen.
The gas diffuses out through stomata.