BGS, BSGS Bachelor of General Studies BSGS Natural Sciences 4 — Questions and Answers
Question 1: Which molecule serves as the primary energy currency of the cell?
- ADP
- NADH
- ATP (Correct answer)
- FADH₂
Correct answer: ATP
Adenosine triphosphate (ATP) stores and transfers chemical energy for nearly all cellular processes.
Question 2: What is the speed of light in a vacuum?
- 3 × 10⁶ m/s
- 3 × 10⁸ m/s (Correct answer)
- 3 × 10¹⁰ m/s
- 3 × 10¹² m/s
Correct answer: 3 × 10⁸ m/s
Light travels at approximately 3 × 10⁸ m/s (about 300,000 km/s) in a vacuum, denoted as c.
Question 3: In the water cycle, which process directly converts liquid water into water vapor without reaching boiling point?
- Condensation
- Precipitation
- Evaporation (Correct answer)
- Sublimation
Correct answer: Evaporation
Evaporation occurs when water molecules at the liquid surface gain enough kinetic energy to escape into the atmosphere.
Question 4: Which subatomic particle determines the atomic number of an element?
- Neutron
- Electron
- Proton (Correct answer)
- Positron
Correct answer: Proton
The atomic number equals the number of protons in the nucleus, uniquely identifying each element on the periodic table.
Question 5: What is the term for symbiosis in which one organism benefits and the other is neither helped nor harmed?
- Mutualism
- Parasitism
- Commensalism (Correct answer)
- Competition
Correct answer: Commensalism
Commensalism describes a relationship where one species benefits (e.g., remora fish on sharks) while the host is unaffected.
Question 6: Which law states that the total pressure of a gas mixture equals the sum of the partial pressures of each component gas?
- Boyle's law
- Charles's law
- Dalton's law (Correct answer)
- Gay-Lussac's law
Correct answer: Dalton's law
Dalton's law of partial pressures states P_total = P₁ + P₂ + … + Pₙ for a mixture of non-reacting gases.
Question 7: During photosynthesis, the light-dependent reactions occur in which structure of the chloroplast?
- Stroma
- Thylakoid membrane (Correct answer)
- Outer membrane
- Matrix
Correct answer: Thylakoid membrane
Light-dependent reactions take place in the thylakoid membranes, where chlorophyll absorbs light to drive the splitting of water and synthesis of ATP and NADPH.
BGS, BSGS Bachelor of General Studies BSGS Natural Sciences 4
Which molecule serves as the primary energy currency of the cell?