Explanation

• Residual volume (RV) is the volume of air that remains in the lungs after maximum forced expiration.
• It cannot be voluntarily exhaled completely.
• It helps prevent the lungs from collapsing.
• It is different from normal tidal breathing.

Last verified on 01-10-2026

Explanation

• The two strands of DNA run in opposite directions (5' to 3' on one strand and 3' to 5' on the other).
• This orientation is known as antiparallel.
• It is crucial for proper DNA replication and function.

Last verified on 01-10-2026

Explanation

• The nucleus contains the cell’s genetic material (DNA).
• DNA carries hereditary information.
• The nucleus controls many cell activities.
• In prokaryotic cells (like bacteria), DNA is not enclosed in a nucleus; it is found in the nucleoid region.
• Genetic material = DNA.

Explanation

• Total bones in adult human body = 206
• At birth = 270–300 bones (fuse to become 206)

The total bones of our body can be divided into:

• Axial skeleton = 80 bones
• Appendicular skeleton = 126 bones

Additional information:

• Newborn baby has 300 bones
• Longest bone = Femur
• Shortest bone = Stapes
• Bones in human skull = 22

Last verified on 30-03-2026

Explanation

• Inventor: Thomas Alva Edison.
• Country: United States.
• Practical incandescent bulb: 1879.
• Other contributions: Electric power, sound recording, motion pictures.
• Famous invention: Phonograph.

Last verified on 03-09-2026

Explanation

• Mercury is the closest planet to the Sun, followed by Venus.
• Called an inner planet because it orbits inside Earth’s orbit.
• Number of moons: 0 (Mercury has no natural satellites).
• Size: Smallest planet in the solar system.
• Nickname: Swift Planet, due to its fast orbit around the Sun (≈88 days per orbit).

Last verified on 17-03-2026

Explanation

• The Hubble Space Telescope is a joint project of NASA (USA) and ESA (European Space Agency).
• It was launched in 1990 into low Earth orbit.
• Scientists like John C. Mather contributed to its development and research.
• It is used for observing distant galaxies and space objects.

Last verified on 08-06-2026

Explanation

• Earth is the third planet from the Sun in our solar system.

The order of the planets starting closest to the Sun is:

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

Last verified on 27-09-2026

Explanation

• Saturn is famous for its prominent and beautiful ring system.
• Its rings are made mainly of ice particles, dust, and rock fragments.

Additional information:

• It is the second-largest planet in the Solar System.
• It is often called the “Ringed Planet.”
• Famous moon: Titan
• Orbital period: About 29.5 Earth years
• It is the sixth planet from the Sun.

Last verified on 27-09-2026

Explanation

• Geology means the study of the Earth.
• It is also called Earth Science or Geoscience.
• Geology studies the formation, structure, composition, and history of Earth.
• It also examines the processes acting on Earth, such as earthquakes, volcanoes, and erosion.
• A person who studies geology is called a geologist.

Last verified on 15-09-2026