Explanation

P waves (primary waves) are the fastest seismic waves generated during an earthquake.

They travel through solids, liquids, and gases, compressing and expanding the material.

S waves (secondary waves) are slower and can only move through solids.

P waves are the first to be detected by seismographs.

Their higher speed helps in early warning systems for earthquakes.

Explanation

Glucose is mainly synthesized in plants through photosynthesis.

Carbon dioxide provides the carbon atoms needed for glucose formation.

Water (H₂O) provides hydrogen and electrons but does not contribute carbon.

Explanation

The main purpose of cellular respiration is to convert chemical energy stored in nutrients (specifically glucose) into ATP (adenosine triphosphate),

They acts as the usable energy currency for cellular processes.

It breaks down glucose in the presence of oxygen to produce ATP, carbon dioxide, and water. 

Explanation

Cellular activities require energy to function, which comes from molecules like ATP.

ATP (adenosine triphosphate) stores energy in its phosphate bonds.

When a phosphate bond is broken, energy is released for cellular processes.

This energy powers activities like muscle contraction, nerve signaling, and biosynthesis.

Therefore, phosphate bonds are the primary source of energy in metabolism.

Explanation

Noble gas atoms generally do not form bonds under normal conditions

Due to their full valence electron shells, making them highly stable and inert.

However, under extreme pressure, low temperatures, or with highly reactive elements like fluorine and oxygen,

They can form compound bonds, primarily involving heavier gases like xenon. 

Explanation

LPG (Liquefied Petroleum Gas)

Mainly consists of hydrocarbons like propane and butane.

These are gases composed of hydrogen and carbon atoms.

It is used as fuel for cooking and heating.

Explanation

The Sun produces energy through nuclear fusion in its core.

In fusion, hydrogen nuclei combine to form helium, releasing huge energy.

This energy radiates as sunlight, heat, and solar radiation.

Fusion is different from fission, which splits heavy nuclei.

Solar energy powers life on Earth and can be harnessed for electricity.

Explanation

Perihelion is the point in a comet’s orbit closest to the Sun.

According to Kepler’s Second Law, a comet moves faster when closer to the Sun.

Aphelion is the farthest point from the Sun, where speed is minimum.

The increase in speed is due to Sun’s gravitational pull.

This principle applies to all celestial bodies in elliptical orbits.

Explanation

A cell is the basic structural and functional unit of life.

All plant and animal tissues are made up of cells.

Nitrogen, phosphorus, and oxygen are elements, not units of tissue.

Explanation

• The study of humans has multiple branches focusing on biology, culture, and history.
• Anthropology specifically studies the evolution and biological development of humans.
• It examines humans as part of the animal kingdom and their physical, social, and cultural traits.

Last verified on 22-01-2026