BS Bachelor of Science: Life, Physical, and Chemical 5 — Questions and Answers
Question 1: Which scientist proposed the theory of natural selection as a mechanism for evolution?
- Gregor Mendel
- Louis Pasteur
- Charles Darwin (Correct answer)
- James Watson
Correct answer: Charles Darwin
Charles Darwin published 'On the Origin of Species' in 1859, proposing natural selection as the driving mechanism of evolution.
Question 2: Which gas law describes the inverse relationship between the pressure and volume of a gas at constant temperature?
- Charles's law
- Boyle's law (Correct answer)
- Gay-Lussac's law
- Avogadro's law
Correct answer: Boyle's law
Boyle's law states that pressure and volume are inversely proportional at constant temperature (PV = constant).
Question 3: Which type of ecological relationship benefits one organism while the other is neither harmed nor helped?
- Mutualism
- Parasitism
- Commensalism (Correct answer)
- Competition
Correct answer: Commensalism
Commensalism benefits one species while the other is unaffected, such as barnacles living on whale skin.
Question 4: In the electromagnetic spectrum, which type of radiation is used in MRI (magnetic resonance imaging) machines?
- X-rays
- Ultraviolet radiation
- Radio waves (Correct answer)
- Infrared radiation
Correct answer: Radio waves
MRI machines use radio waves combined with strong magnetic fields to produce detailed images of internal body structures.
Question 5: What is the SI unit of electric charge?
- Ampere
- Volt
- Coulomb (Correct answer)
- Ohm
Correct answer: Coulomb
The coulomb (C) is the SI unit of electric charge, equal to the charge transferred by one ampere in one second.
Question 6: Which process converts atmospheric nitrogen (N₂) into ammonia (NH₃), making it usable by living organisms?
- Denitrification
- Nitrification
- Nitrogen fixation (Correct answer)
- Ammonification
Correct answer: Nitrogen fixation
Nitrogen fixation converts inert N₂ gas into ammonia, carried out by bacteria such as Rhizobium in root nodules.
Question 7: Which type of isomers have the same molecular formula and connectivity but differ in the spatial arrangement of atoms around a double bond?
- Constitutional isomers
- Enantiomers
- Geometric (cis-trans) isomers (Correct answer)
- Conformational isomers
Correct answer: Geometric (cis-trans) isomers
Geometric isomers (cis-trans isomers) differ in the spatial arrangement of substituents around a restricted double bond.
BS Bachelor of Science: Life, Physical, and Chemical 5
Which scientist proposed the theory of natural selection as a mechanism for evolution?